Author: "Universität Bremen" / Topic: 010504 meteorology & atmospheric sciences - Searchworks@Jio Institute Digital Library Search Results

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173 results on '"Universität Bremen"'

1. A wind-driven model of the ocean surface layer with wave radiation physics

Author: Olbers, Dirk, Jurgenowski, Philipp, Eden, Carsten, MARUM – Center for Marine Environmental Sciences, Universität Bremen, Bremen, Germany, and Institut für Meereskunde, Universität Hamburg, Hamburg, Germany
Subjects: Physics, Wave radiation physics, 010504 meteorology & atmospheric sciences, 010505 oceanography, Mixed layer, Mechanics, Radiation, Dissipation, Oceanography, 01 natural sciences, ddc:551.5, Coriolis frequency, Slab, Surface layer, Wind-driven internal gravity waves, Mixing (physics), Pressure gradient, 0105 earth and related environmental sciences
Abstract: Surface windstress transfers energy to the surface mixed layer of the ocean, and this energy partly radiates as internal gravity waves with near-inertial frequencies into the stratified ocean below the mixed layer where it is available for mixing. Numerical and analytical models provide estimates of the energy transfer into the mixed layer and the fraction radiated into the interior, but with large uncertainties, which we aim to reduce in the present study. An analytical slab model of the mixed layer used before in several studies is extended by consistent physics of wave radiation into the interior. Rayleigh damping, controlling the physics of the original slab model, is absent in the extended model and the wave-induced pressure gradient is resolved. The extended model predicts the energy transfer rates, both in physical and wavenumber-frequency space, associated with the wind forcing, dissipation in the mixed layer, and wave radiation at the base as function of a few parameters: mixed layer depth, Coriolis frequency and Brunt-Väisälä frequency below the mixed layer, and parameters of the applied windstress spectrum. The results of the model are satisfactorily validated with a realistic numerical model of the North Atlantic Ocean., Deutsche Forschungsgemeinschaft https://doi.org/10.13039/501100001659
Published: 2020

2. Multiproxy assessment of Holocene relative sea-level changes in the western Mediterranean: Sea-level variability and improvements in the definition of the isostatic signal

Author: Nick Marriner, Alessandro Fontana, Alessio Rovere, Christophe Morhange, Matteo Vacchi, Giorgio Spada, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Laboratoire Chrono-environnement - UFC (UMR 6249) (LCE), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Laboratoire Chrono-environnement - CNRS - UBFC (UMR 6249) (LCE), Centre européen de recherche et d'enseignement de géosciences de l'environnement ( CEREGE ), Centre National de la Recherche Scientifique ( CNRS ) -Institut de Recherche pour le Développement ( IRD ) -Aix Marseille Université ( AMU ) -Collège de France ( CdF ) -Institut National de la Recherche Agronomique ( INRA ) -Institut national des sciences de l'Univers ( INSU - CNRS ), Laboratoire Chrono-environnement ( LCE ), Université Bourgogne Franche-Comté ( UBFC ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), MARUM, Universität Bremen Postfach, Vacchi, Matteo, Marriner, Nick, Morhange, Christophe, SPADA, GIORGIO, Fontana, Alessandro, and Rovere, Alessio
Subjects: Mediterranean climate, Isostasy, 010504 meteorology & atmospheric sciences, Antarctic ice sheet, Context (language use), Sea-level database, Sea level, Isostasy, Mediterranean Sea, Holocene, 010502 geochemistry & geophysics, 01 natural sciences, Mediterranean sea, Isostatic adjustment, Settore GEO/04 - Geografia Fisica e Geomorfologia, Mediterranean Sea, Sea level, Holocene, Sea-level proxy, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, 14. Life underwater, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Beachrock, [ SDU.STU.GM ] Sciences of the Universe [physics]/Earth Sciences/Geomorphology, Earth and Planetary Sciences (all), Oceanography, 13. Climate action, General Earth and Planetary Sciences, Spatial variability, Geology
Abstract: A review of 917 relative sea-level (RSL) data-points has resulted in the first quality-controlled database constraining the Holocene sea-level histories of the western Mediterranean Sea (Spain, France, Italy, Slovenia, Croatia, Malta and Tunisia). We reviewed and standardized the geological RSL data-points using a new multi-proxy methodology based on: (1) modern taxa assemblages in Mediterranean lagoons and marshes; (2) beachrock characteristics (cement fabric and chemistry, sedimentary structures); and (3) the modern distribution of Mediterranean fixed biological indicators. These RSL data-points were coupled with the large number of archaeological RSL indicators available for the western Mediterranean. We assessed the spatial variability of RSL histories for 22 regions and compared these with the ICE-5G (VM2) GIA model. In the western Mediterranean, RSL rose continuously for the whole Holocene with a sudden slowdown at ~ 7.5 ka BP and a further deceleration during the last ~ 4.0 ka BP, after which time observed RSL changes are mainly related to variability in isostatic adjustment. The sole exception is southern Tunisia, where data show evidence of a mid-Holocene high-stand compatible with the isostatic impacts of the melting history of the remote Antarctic ice sheet. Our results indicate that late-Holocene sea-level rise was significantly slower than the current one. First estimates of GIA contribution indicate that, at least in the northwestern sector, it accounts at least for the 25–30% of the ongoing sea-level rise recorded by Mediterranean tidal gauges. Such contribution is less constrained at lower latitudes due to the lower quality of the late Holocene index points. Future applications of spatio-temporal statistical techniques are required to better quantify the gradient of the isostatic contribution and to provide improved context for the assessment of 20th century acceleration of Mediterranean sea-level rise.
Published: 2016

3. Linking zooplankton time series to the fossil record

Author: Thibault de Garidel-Thoron, Marina C. Rillo, John A. Kitchener, Lukas Jonkers, Michal Kucera, Julie Meilland, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: 0106 biological sciences, Series (stratigraphy), Fossil Record, 010504 meteorology & atmospheric sciences, Ecology, 010604 marine biology & hydrobiology, Aquatic Science, Oceanography, 01 natural sciences, Zooplankton, [SDE]Environmental Sciences, Environmental science, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences
Abstract: Marine zooplankton time series are crucial to understand the dynamics of pelagic ecosystems. However, most observational time series are only a few decades long, which limits our understanding of long-term zooplankton dynamics, renders attribution of observed trends to global change ambiguous, and hampers prediction of future response to environmental change. Planktonic foraminifera are calcifying marine zooplankton that have the unique potential to substantially extend our view on plankton dynamics because their skeletal remains are preserved for millions of years in deep-sea sediments. Thus, linking sedimentary and modern time series offers great potential to study zooplankton dynamics across time scales not accessible by direct observations. However, this link is rarely made and the potential of planktonic foraminifera for advancing our understanding of zooplankton dynamics remains underexploited. This underutilization of this potential to bridge time scales is mainly because of the lack of collaboration between biologists, who have mostly focused on other (zoo)plankton, and micropalaeontologists, who have focussed too narrowly on fossil foraminifera. With this food for thought article, we aim to highlight the unique potential of planktonic foraminifera to bridge the gap between biology and geology. We strongly believe that such collaboration has large benefits to both scientific communities.
Published: 2021

4. Genomic evidence for global ocean plankton biogeography shaped by large-scale current systems

Author: Richter, Daniel J., Watteaux, Romain, Vannier, Thomas, Leconte, Jade, Frémont, Paul, Reygondeau, Gabriel, Maillet, Nicolas, Henry, Nicolas, Benoit, Gaëtan, da Silva, Ophélie, Delmont, Tom O., Fernández-Guerra, Antonio, Suweis, Samir, Narci, Romain, Berney, Cedric, Eveillard, Damien, Gavory, Frederick, Guidi, Lionel, Labadie, Karine, Mahieu, Eric, Poulain, Julie, Romac, Sarah, Roux, Simon, Dimier, Céline, Kandels‐Lewis, Stefanie, Picheral, Marc, Searson, Sarah, Oceans, Tara, Pesant, Stéphane, Aury, Jean-Marc, Brum, Jennifer R., Lemaitre, Claire, Pelletier, Eric, Bork, Peer, Sunagawa, Shinichi, Lombard, Fabien, Karp-Boss, Lee, Bowler, Chris, Sullivan, Matthew B., Karsenti, Eric, Mariadassou, Mahendra, Probert, Ian, Peterlongo, Pierre, Wincker, Patrick, Vargas, Colomban de, Ribera d’Alcalà, Maurizio, Iudicone, Daniele, Jaillon, Olivier, Tara Oceans Coordinators, Centre National de la Recherche Scientifique (France), European Molecular Biology Laboratory, Centre National de Séquençage (France), National Fund for Scientific Research (Belgium), Stazione Zoologica Anton Dohrn, Università degli Studi di Milano, Université Paris Sciences & Lettres, Agence Nationale de la Recherche (France), National Science Foundation (US), Veolia Foundation, Région Bretagne, World Courier, Illumina, Cap L’Orient, Fondation EDF, Fondation pour la Recherche sur la Biodiversité, Fondation Prince Albert II de Monaco, Ministère de l'Europe et des Affaires étrangères (France), Adaptation et diversité en milieu marin (ADMM), Institut national des sciences de l'Univers (INSU - CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Stazione Zoologica Anton Dohrn (SZN), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut de Génomique d'Evry (IG), Université Paris-Saclay-Institut de Biologie François JACOB (JACOB), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Genoscope - Centre national de séquençage [Evry] (GENOSCOPE), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), University of British Columbia (UBC), Hub Bioinformatique et Biostatistique - Bioinformatics and Biostatistics HUB, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Max Planck Institute for Marine Microbiology, Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Università degli Studi di Padova = University of Padua (Unipd), Consorzio Nazionale Interuniversitario per le Scienze FIsiche della Materia (CNISM), Mathématiques et Informatique Appliquées du Génome à l'Environnement [Jouy-En-Josas] (MaIAGE), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Numérique de Nantes (LS2N), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Combinatoire et Bioinformatique (LS2N - équipe COMBI), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Institut de Biologie François JACOB (JACOB), Ohio State University [Columbus] (OSU), Institut de biologie de l'ENS Paris (IBENS), Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Ecology and Evolutionary Biology [Tucson] (EEB), University of Arizona, Scalable, Optimized and Parallel Algorithms for Genomics (GenScale), Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-GESTION DES DONNÉES ET DE LA CONNAISSANCE (IRISA-D7), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Rennes 1 (UR1), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), European Molecular Biology Laboratory [Heidelberg] (EMBL), University of Maine, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Fédération de recherche de Roscoff (FR2424), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), French National Research Agency (ANR)HYDROGEN/ANR-14CE23-0001, National Science Foundation (NSF)OCE-1536989, OCE-1829831, Commissariat a l'Energie Atomique et aux Energies Alternatives, Graphene Flagship, European Project: 634486,H2020,H2020-BG-2014-2,INMARE(2015), European Project: 287589,EC:FP7:KBBE,FP7-OCEAN-2011,MICRO B3(2012), Adaptation et diversité en milieu marin (AD2M), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Universita degli Studi di Padova, Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Combinatoire et Bioinformatique (COMBI), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff (SBR), Centre de Mathématiques et de Leurs Applications (CMLA), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)-Aix Marseille Université (AMU)-Institut de Recherche pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS)-Institut Pasteur [Paris], Infectiologie Santé Publique (ISP-311), Institut National de la Recherche Agronomique (INRA)-Université de Tours, Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA), Laboratoire d'Informatique de Nantes Atlantique (LINA), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), Institut de biologie de l'ENS Paris (UMR 8197/1024) (IBENS), École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université de Bretagne Sud (UBS)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National de Recherche en Informatique et en Automatique (Inria)-École normale supérieure - Rennes (ENS Rennes)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-CentraleSupélec-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Bretagne Sud (UBS)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-École normale supérieure - Rennes (ENS Rennes)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1)
Subjects: 010504 meteorology & atmospheric sciences, Biogeography, Oceans and Seas, Context (language use), 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, 03 medical and health sciences, plankton biogeography, genomics, Ecosystem, genetics, 14. Life underwater, microbial oceanography, 030304 developmental biology, 0105 earth and related environmental sciences, Seascape, [SDV.EE]Life Sciences [q-bio]/Ecology, environment, 0303 health sciences, metagenomics, General Immunology and Microbiology, Geography, General Neuroscience, Ocean current, fungi, Community structure, General Medicine, 15. Life on land, Plankton, Oceanography, 13. Climate action, Metagenomics, metabarcoding, ecology, [INFO.INFO-BI]Computer Science [cs]/Bioinformatics [q-bio.QM]
Abstract: Biogeographical studies have traditionally focused on readily visible organisms, but recent technological advances are enabling analyses of the large-scale distribution of microscopic organisms, whose biogeographical patterns have long been debated. Here we assessed the global structure of plankton geography and its relation to the biological, chemical, and physical context of the ocean (the ‘seascape’) by analyzing metagenomes of plankton communities sampled across oceans during the Tara Oceans expedition, in light of environmental data and ocean current transport. Using a consistent approach across organismal sizes that provides unprecedented resolution to measure changes in genomic composition between communities, we report a pan-ocean, size-dependent plankton biogeography overlying regional heterogeneity. We found robust evidence for a basin-scale impact of transport by ocean currents on plankton biogeography, and on a characteristic timescale of community dynamics going beyond simple seasonality or life history transitions of plankton., We thank the commitment of the following people and sponsors who made this expedition possible: CNRS (in particular Groupement de Recherche GDR3280), European Molecular Biology Laboratory (EMBL), Genoscope/CEA, Fund for Scientific Research – Flanders, VIB, Stazione Zoologica Anton Dohrn, UNIMIB, Paris Sciences et Lettres (PSL) Research University (ANR-11-IDEX-0001–02), the French Government ANR (projects FRANCE GENOMIQUE/ANR-10-INBS-09, MEMO LIFE/ANR-10-LABX-54, POSEIDON/ANR-09-BLAN-0348, PROMETHEUS/ANR-09-PCS-GENM-217, MAPPI/ANR-2010-COSI-004, TARA-GIRUS/ANR-09-PCS-GENM-218), US NSF grant DEB-1031049, FWO, BIO5, Biosphere 2, Agnès b., the Veolia Environment Foundation, Région Bretagne, World Courier, Illumina, Cap L’Orient, the EDF Foundation EDF Diversiterre, FRB, the Prince Albert II de Monaco Foundation, Etienne Bourgois, the Tara schooner and its captain and crew. We thank MERCATOR-CORIOLIS and ACRI-ST for providing daily satellite data during the expedition. The bulk of genomic computations were performed using the Airain HPC machine provided through GENCI- [TGCC/CINES/IDRIS] (grants t2011076389, t2012076389, t2013036389, t2014036389, t2015036389 and t2016036389). We are also grateful to the French Ministry of Foreign Affairs for supporting the expedition and to the countries who granted us sampling permissions.
Published: 2022

5. Carbon stocks and isotopic budgets of the terrestrial biosphere at mid-Holocene and last glacial maximum times

Author: Gilles Ramstein, Pierre Warnant, Stephan Lorenz, Nathalie de Noblet, Yves Goddéris, Louis François, Laboratoire de Physique Atmosphérique et Planétaire (LPAP), Université de Liège, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Modélisation du climat (CLIM), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Extrèmes : Statistiques, Impacts et Régionalisation (ESTIMR), Fachbereicht Geowissenschaften, Universität Bremen, Universität Bremen, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: ECHAM, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Biomass (ecology), 010504 meteorology & atmospheric sciences, Pleistocene, Biosphere, Geology, Last Glacial Maximum, Vegetation, 15. Life on land, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, Carbon cycle, 13. Climate action, Geochemistry and Petrology, Climatology, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Holocene, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: The carbon fluxes, stocks and isotopic budgets of the land biosphere at mid-Holocene (6 ka BP) and last glacial maximum (21 ka BP) times are reconstructed with the CARbon Assimilation In the Biosphere (CARAIB) model forced with two different sets of climates simulated by the European Centre-HAMburg (ECHAM) and LMD general circulation models. It is found that the trends predicted on the basis of both sets of GCM climatic fields are generally consistent with each other, although substantial discrepancies in the magnitude of the changes may be observed. Actually, these discrepancies in the biospheric results associated with the use of different GCM climatic fields are usually smaller than the differences between biospheric runs performed while considering or neglecting the CO2 fertilization effect (which might, however, be overestimated by the model due to uncertainties concerning changes in nutrient availability). The calculated changes with respect to the present of the biosphere carbon stock range from −132 to +92 Gt C for the mid-Holocene and from −710 to +70 Gt C for the last glacial maximum. It is also shown that the relative contribution of the material synthesized by C4 plants to the total biomass of vegetation, litter and soils was substantially larger at mid-Holocene and last glacial maximum times than today. This change in the relative importance of the C3 and C4 photosynthetic pathways induced changes in the 13 C fractionation of the land biosphere. These changes in the average biospheric fractionation resulting from the redistribution of C3 and C4 plants were partly compensated for by changes of opposite sign in the fractionation of C3 plants due to the modification of the intercellular CO2 pressure within their leaves. With respect to present times, the combination of both processes reduced the 13 C discrimination (i.e., less negative fractionation) of the land biosphere by 0.03 to 0.32‰ during the mid-Holocene and by 0.30 to 1.86‰ at the last glacial maximum.
Published: 1999

6. Early Paleocene Paleoceanography and Export Productivity in the Chicxulub Crater

Author: Lowery C.M., Jones H.L., Bralower T.J., Cruz L.P., Gebhardt C., Whalen M.T., Chenot E., Smit J., Phillips M.P., Choumiline K., Arenillas I., Arz J.A., Garcia F., Ferrand M., Gulick S.P.S., Christeson G., Claeys P., Cockell C., Coolen M., Ferrière L., Goto K., Green S., Grice K., Kring D., Lofi J., Mellett C., Morgan J., Ocampo-Torres R., Pickersgill A., Poelchau M., Rae A., Rasmussen C., Rebolledo-Vieyra M., Riller U., Sato H., Schaefer B., Tikoo S., Tomioka N., Urrutia-Fucugauchi J., Wittmann A., Xiao L., Yamaguchi K., Zylberman W., Expedition 364 Science Party, Institute for Geophysics, University of Texas, University of Texas at Austin [Austin], Department of Geosciences [PennState], College of Earth and Mineral Sciences, Pennsylvania State University (Penn State), Penn State System-Penn State System-Pennsylvania State University (Penn State), Penn State System-Penn State System, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Instituto de Geofisica [Mexico], Universidad Nacional Autónoma de México (UNAM), Alfred Wegener Institute for Polar and Marine Research (AWI), Department of Geosciences, University of Alaska [Fairbanks] (UAF), Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS), Institut Polytechnique LaSalle Beauvais, Faculty of Earth and Life Sciences [Amsterdam] (FALW), Vrije Universiteit Amsterdam [Amsterdam] (VU), Department of Earth Sciences [Riverside], University of California [Riverside] (UCR), University of California-University of California, Departamento de Ciencias de la Tierra, University of Zaragoza - Universidad de Zaragoza [Zaragoza], Instituto Universitario en investigación en Ciencias Ambientales de Aragón (IUCA), Biogéosciences [UMR 6282] [Dijon] (BGS), Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique (CNRS), Department of Geological Sciences [Austin], Jackson School of Geosciences (JSG), University of Texas at Austin [Austin]-University of Texas at Austin [Austin], Center for Planetary Systems Habitability, University of Texas at Austin [Austin]-Jackson School of Geosciences, and Geology and Geochemistry
Subjects: bepress|Physical Sciences and Mathematics|Earth Sciences|Paleontology, bepress|Physical Sciences and Mathematics, bepress|Physical Sciences and Mathematics|Earth Sciences|Sedimentology, 010506 paleontology, Atmospheric Science, 010504 meteorology & atmospheric sciences, bepress|Physical Sciences and Mathematics|Earth Sciences, EarthArXiv|Physical Sciences and Mathematics|Earth Sciences, 010502 geochemistry & geophysics, Oceanography, 01 natural sciences, Foraminifera, Water column, Impact crater, Paleoceanography, Phytoplankton, Photic zone, 14. Life underwater, SDG 14 - Life Below Water, EarthArXiv|Physical Sciences and Mathematics|Earth Sciences|Sedimentology, 0105 earth and related environmental sciences, biology, Terrigenous sediment, Paleontology, EarthArXiv|Physical Sciences and Mathematics|Earth Sciences|Geochemistry, 15. Life on land, EarthArXiv|Physical Sciences and Mathematics|Earth Sciences|Paleontology, biology.organism_classification, humanities, EarthArXiv|Physical Sciences and Mathematics, Productivity (ecology), 13. Climate action, [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Environmental science, bepress|Physical Sciences and Mathematics|Earth Sciences|Geochemistry
Abstract: The Chicxulub impact caused a crash in productivity in the world''s oceans which contributed to the extinction of ~75% of marine species. In the immediate aftermath of the extinction, export productivity was locally highly variable, with some sites, including the Chicxulub crater, recording elevated export production. The long-term transition back to more stable export productivity regimes has been poorly documented. Here, we present elemental abundances, foraminifer and calcareous nannoplankton assemblage counts, total organic carbon, and bulk carbonate carbon isotope data from the Chicxulub crater to reconstruct changes in export productivity during the first 3 Myr of the Paleocene. We show that export production was elevated for the first 320 kyr of the Paleocene, declined from 320 kyr to 1.2 Myr, and then remained low thereafter. A key interval in this long decline occurred 900 kyr to 1.2 Myr post impact, as calcareous nannoplankton assemblages began to diversify. This interval is associated with fluctuations in water column stratification and terrigenous flux, but these variables are uncorrelated to export productivity. Instead, we postulate that the turnover in the phytoplankton community from a post-extinction assemblage dominated by picoplankton (which promoted nutrient recycling in the euphotic zone) to a Paleocene pelagic community dominated by relatively larger primary producers like calcareous nannoplankton (which more efficiently removed nutrients from surface waters, leading to oligotrophy) is responsible for the decline in export production in the southern Gulf of Mexico. © 2021. American Geophysical Union. All Rights Reserved.
Published: 2021

7. Assessing Spatio‐Temporal Variability of Free Gas in Surficial Cohesive Sediments Using Tidal Pressure Fluctuations

Author: Ronan Apprioual, Christoph Witt, Bruno Marsset, Achim J Kopf, Yannick Thomas, Patrice Woerther, Xavier Bompais, Sebastien Garziglia, Stephan Ker, Nabil Sultan, Unité de recherche Géosciences Marines (Ifremer) (GM), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Unité de recherche Recherches et Développements Technologiques [Plouzané], Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, and ANR-17-EURE-0015,ISBlue,Interdisciplinary Graduate School for the Blue planet(2017)
Subjects: 010504 meteorology & atmospheric sciences, Free gas, geohazards, long-term in situ monitoring, inverse modeling, 010502 geochemistry & geophysics, 01 natural sciences, remote sensing, slope stability, Geophysics, 13. Climate action, Remote sensing (archaeology), [SDU]Sciences of the Universe [physics], Slope stability, Environmental science, 14. Life underwater, Geomorphology, free gas dynamics, 0105 earth and related environmental sciences, Earth-Surface Processes
Abstract: From a geohazard assessment perspective, the distribution, content and dynamics of free gas in surficial sediment was addressed by imaging and monitoring the upper 15 m beneath the shelf offshore Nice, France. Based on high resolution seismic data covering three sites where pore pressure was recorded over three and a half years, the presence of free gas was determined in the upper 2.75 to 14.75 m of cohesive, silty clay. Seismic velocity changes delineate two layers with gas volume fraction ranging from 0.12 % to 1.89 %. By considering the tidal response recorded by eight pore pressure sensors, gas volume fractions were estimated to vary from 0.26% to more than 9.4% on a spatio-temporal scale which cannot be achieved with seismic data. To depict spatio-temporal patterns three types of free gas occurrence (FGO) were distinguished. The one uniquely characterized by sawtooth fluctuations in overpressure of 27% to 45 % of the hydrostatic effective stress was recognized as an occurrence where bubbles grow and rise. The other two types showed long-term overpressure trends indicative of a situation whereby bubble growth has ceased. Type 1 FGOs are distinguished from type 2 by their gas volume fraction lower than 9.4 % and ratios of overpressure to hydrostatic effective stress lower than 0.3. Values higher than this threshold are considered sufficient for shear failure to initiate from the steep shelf edge (> 20°). Beyond site-specific insights, the distinction of FGO from their overpressure levels yields testable implications for the dynamics of methane in sediments. Plain Language Summary Increased awareness of the role of gas bubbles in surficial sediments with regard to the stability of submarine slopes have stressed the need to quantify their distribution, content and evolution with time. This was addressed by imaging and recording pressure fluctuations of shallow subsurface marine sediments. Both methods agreed in delineating the broad distribution of gas in these clayey deposits. However, they provided contrasting estimates of gas content which could be related to their distinct sensitivity to local changes. The analysis of the results obtained from the pressure records led to the recognition of three types of gas accumulations which cannot be discerned by imaging the subsurface. One type distinguishes from the others by showing episodic fluctuations in gas content and pressure ascribed to the growth and rise of bubbles. The other two types show trends in pressure suggesting that bubble growth has ceased. Of these two types, the one which is characterized by the highest gas content and pressure level is also considered to have the potential to initiate local shear failure in sediment. On a broader perspective, field evidences reported in this study provide constraints and testable implications for models addressing the transfer of methane to the atmosphere.
Published: 2021

8. Early Holocene greening of the Sahara requires Mediterranean winter rainfall

Author: Enno Schefuß, Matthieu Carré, Louis François, Rachid Cheddadi, Roger Manay, Ali Rhoujjati, Majda Nourelbait, Diana Ochoa, Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Variabilité à long terme du climat de l'océan (VALCO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université Chouaib Doukkali (UCD), Université de Liège, Laboratoire de Géo-ressources, Unité associée au CNRST (URAC 42) (LGR), Université Cadi Ayyad [Marrakech] (UCA), Universidad Peruana Cayetano Heredia (UPCH), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, ANR-15-MASC-0003,VULPES,VULnerability of Populations under Extreme Scenarios(2015), ANR-15-JCLI-0003,PACMEDY,PAlaeo-Constraints on Monsoon Evolution and Dynamics(2015), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226, Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)
Subjects: Mediterranean climate, 010504 meteorology & atmospheric sciences, Orbital forcing, Environmental change, paleoclimate reconstructions, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 010502 geochemistry & geophysics, Monsoon, 01 natural sciences, vegetation model simulations, Earth, Atmospheric, and Planetary Sciences, green Sahara, Paleoclimatology, purl.org/pe-repo/ocde/ford#1.05.03 [https], Precipitation, Holocene, 0105 earth and related environmental sciences, African humid period, Multidisciplinary, Vegetation, 15. Life on land, 13. Climate action, Physical Sciences, Environmental science, Physical geography
Abstract: Significance Explaining the greening of the Sahara during the Holocene has been a challenge for decades. A strengthening of the African monsoon caused by increased summer insolation is usually cited to explain why the Sahara was vegetated from 14,000 to 5,000 y ago. Here, we provide a unique climate record of quantified winter, spring, and summer precipitation in Morocco over the past 18,500 y, and numeric simulations, which show that moisture contributions from the Mediterranean Sea and the North Atlantic Ocean in winter, were as important as the expanded summer monsoon for the greening of the Sahara during the African humid period. The findings of this study will help to better understand and simulate climate variability over northern Africa., The greening of the Sahara, associated with the African Humid Period (AHP) between ca. 14,500 and 5,000 y ago, is arguably the largest climate-induced environmental change in the Holocene; it is usually explained by the strengthening and northward expansion of the African monsoon in response to orbital forcing. However, the strengthened monsoon in Early to Middle Holocene climate model simulations cannot sustain vegetation in the Sahara or account for the increased humidity in the Mediterranean region. Here, we present an 18,500-y pollen and leaf-wax δD record from Lake Tislit (32° N) in Morocco, which provides quantitative reconstruction of winter and summer precipitation in northern Africa. The record from Lake Tislit shows that the northern Sahara and the Mediterranean region were wetter in the AHP because of increased winter precipitation and were not influenced by the monsoon. The increased seasonal contrast of insolation led to an intensification and southward shift of the Mediterranean winter precipitation system in addition to the intensified summer monsoon. Therefore, a winter rainfall zone must have met and possibly overlapped the monsoonal zone in the Sahara. Using a mechanistic vegetation model in Early Holocene conditions, we show that this seasonal distribution of rainfall is more efficient than the increased monsoon alone in generating a green Sahara vegetation cover, in agreement with observed vegetation. This conceptual framework should be taken into consideration in Earth system paleoclimate simulations used to explore the mechanisms of African climatic and environmental sensitivity.
Published: 2021

9. Juvenile corals underpin coral reef carbonate production after disturbance

Author: Mohsen Kayal, Laetitia Hédouin, Alexandre Mercière, Jordan M. Casey, Diego R. Barneche, Ulisse Cardini, Mehdi Adjeroud, Hunter S. Lenihan, Jérémy Carlot, Valeriano Parravicini, Simon J. Brandl, Alessio Rovere, Benoit Espiau, Centre de recherches insulaires et observatoire de l'environnement (CRIOBE), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Excellence CORAIL (LabEX CORAIL), Université des Antilles (UA)-Institut d'écologie et environnement-Université de la Nouvelle-Calédonie (UNC)-Université de la Polynésie Française (UPF)-Université de La Réunion (UR)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École des hautes études en sciences sociales (EHESS)-Université des Antilles et de la Guyane (UAG)-Institut de Recherche pour le Développement (IRD), Ecologie marine tropicale des océans Pacifique et Indien (ENTROPIE [Nouvelle-Calédonie]), Ifremer - Nouvelle-Calédonie, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Université de la Nouvelle-Calédonie (UNC), University of California, Centre de Synthèse et d’Analyse sur la Biodiversité (CESAB), Fondation pour la recherche sur la Biodiversité (FRB), University of Texas at Austin [Austin], Ecologie marine tropicale des océans Pacifique et Indien (ENTROPIE [Perpignan]), Institut de Recherche pour le Développement (IRD), Stazione Zoologica Anton Dohrn (SZN), Australian Institute of Marine Science (AIMS), Center for Marine Environmental Sciences [Bremen] (MARUM), and Universität Bremen
Subjects: 0106 biological sciences, reef productivity, 010504 meteorology & atmospheric sciences, Coral, Carbonates, 01 natural sciences, Ecosystem services, Settore GEO/04 - Geografia Fisica e Geomorfologia, Coral juveniles, ComputingMilieux_MISCELLANEOUS, General Environmental Science, Global and Planetary Change, geography.geographical_feature_category, Ecology, Coral Reefs, Coral reef, Anthozoa, Reef productivity, population characteristics, geographic locations, Settore BIO/07 - Ecologia, Time series, Climate Change, Climate change, 010603 evolutionary biology, coral juveniles, Animals, Environmental Chemistry, Juvenile, 14. Life underwater, coral assemblages, Reef, Ecosystem, Linear extension, 0105 earth and related environmental sciences, geography, Functional ecology, CaCO3 production, linear extension, fungi, technology, industry, and agriculture, biochemical phenomena, metabolism, and nutrition, Calcification rates, Disturbance (ecology), Coral assemblages, Environmental science, calcification rates, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, time series
Abstract: Sea-level rise is predicted to cause major damage to tropical coastlines. While coral reefs can act as natural barriers for ocean waves, their protection hinges on the ability of scleractinian corals to produce enough calcium carbonate (CaCO3 ) to keep up with rising sea levels. As a consequence of intensifying disturbances, coral communities are changing rapidly, potentially reducing community-level CaCO3 production. By combining colony-level physiology and long-term monitoring data, we show that reefs recovering from major disturbances can produce 40% more CaCO3 than currently estimated due to the disproportionate contribution of juvenile corals. However, the buffering effect of highly productive juvenile corals is compromised by recruitment failures, which have been more frequently observed after large-scale, repeated bleaching events. While the size structure of corals can bolster a critical ecological function on reefs, climate change impacts on recruitment may undermine this buffering effect, thus further compromising the persistence of reefs and their provision of important ecosystem services.
Published: 2021

10. Compositional changes in deglacial red mud event beds off the Laurentian Channel reveal source mixing, grain-size partitioning and ice retreat

Author: Tilo von Dobeneck, Guillaume St-Onge, David J.W. Piper, Aline Govin, Janna Just, Wei Leng, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Bedford Institute of Oceanography, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Climat et Magnétisme (CLIMAG), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut des Sciences de la MER de Rimouski (ISMER), Université du Québec à Rimouski (UQAR), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: Subglacial outburst floods, Environmental Magnetism, 010506 paleontology, Archeology, Gulf of St. Lawrence, 010504 meteorology & atmospheric sciences, Environmental magnetism, Ice stream, Sedimentology-marine cores, 01 natural sciences, Quaternary, Major element analysis, Paleontology, Paleoceanography, Laurentian Channel Ice Stream, Meltwater, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Global and Planetary Change, Red beds, geography, geography.geographical_feature_category, Provenance study, North Atlantic, Sediment, Geology, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, 13. Climate action, Channel (geography)
Abstract: International audience; Between 22 and 17 cal ka BP, five large meltwater events from within the Laurentian Channel Ice Stream deposited mud beds meters thick across a large area of the Laurentian Fan and adjacent continental slopes. This study determines the sources of these event beds and relates them to the glaciological evolution of the retreating Laurentian Ice Stream. We analyzed major element and magnetic mineral contents of these event beds and compare them with a new collection of 80 source reference samples from the Gulf of St. Lawrence area. Element ratios suggest a steady compositional change from older to younger outburst event beds, while element-specific offsets from reference sample compositions indicate grain-size and mineral/element partitioning during suspension transport. Their magnetic properties place event beds on the source mixing trend of four reference samples groups, which represent two magnetite-rich sources (Canadian Shield and/or Southern Newfoundland) and two hematite-rich sources (Appalachian red beds). Using a deterministic linear source mixing model based on IRM 100mT , HIRM and Ca%, we find that the earlier two outburst events had higher contributions from granitic and calcareous sources than the later three events. Combining materials, timing and scenarios of the outburst events with ice-sheet retreat and ice-stream dynamics, we argue that the subglacial sediment depocenter of the earlier two event beds was located in the lower Laurentian Channel while that of the later three events was upstream from Cabot Strait.
Published: 2019

11. The CAMS reanalysis of atmospheric composition

Author: Sebastien Massart, Vincent-Henri Peuch, Samuel Remy, Richard Engelen, Henk Eskes, Michael Schulz, Anne-Marlene Blechschmidt, Anna Agusti-Panareda, Zak Kipling, Juan Jose Dominguez, Jerome Barre, Antje Inness, Johannes Flemming, Martin Suttie, Vincent Huijnen, M. Razinger, Anna Benedictow, Melanie Ades, L. Jones, Mark Parrington, European Centre for Medium-Range Weather Forecasts (ECMWF), Atmospheric Chemistry Observations and Modeling Laboratory (ACOML), National Center for Atmospheric Research [Boulder] (NCAR), Norwegian Meteorological Institute, Universität Bremen, Royal Netherlands Meteorological Institute (KNMI), Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique (CERFACS), CERFACS, Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Norwegian Meteorological Institute [Oslo] (MET), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and École normale supérieure - Paris (ENS-PSL)
Subjects: Horizontal resolution, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 0303 health sciences, Atmospheric Science, 010504 meteorology & atmospheric sciences, 010501 environmental sciences, 01 natural sciences, lcsh:QC1-999, Atmospheric composition, Troposphere, Atmosphere, lcsh:Chemistry, 03 medical and health sciences, lcsh:QD1-999, 13. Climate action, Greenhouse gas, Climatology, Temporal resolution, Satellite, Optical depth, lcsh:Physics, 030304 developmental biology, 0105 earth and related environmental sciences
Abstract: The Copernicus Atmosphere Monitoring Service (CAMS) reanalysis is the latest global reanalysis dataset of atmospheric composition produced by the European Centre for Medium-Range Weather Forecasts (ECMWF), consisting of three-dimensional time-consistent atmospheric composition fields, including aerosols and chemical species. The dataset currently covers the period 2003–2016 and will be extended in the future by adding 1 year each year. A reanalysis for greenhouse gases is being produced separately. The CAMS reanalysis builds on the experience gained during the production of the earlier Monitoring Atmospheric Composition and Climate (MACC) reanalysis and CAMS interim reanalysis. Satellite retrievals of total column CO; tropospheric column NO2; aerosol optical depth (AOD); and total column, partial column and profile ozone retrievals were assimilated for the CAMS reanalysis with ECMWF's Integrated Forecasting System. The new reanalysis has an increased horizontal resolution of about 80 km and provides more chemical species at a better temporal resolution (3-hourly analysis fields, 3-hourly forecast fields and hourly surface forecast fields) than the previously produced CAMS interim reanalysis. The CAMS reanalysis has smaller biases compared with most of the independent ozone, carbon monoxide, nitrogen dioxide and aerosol optical depth observations used for validation in this paper than the previous two reanalyses and is much improved and more consistent in time, especially compared to the MACC reanalysis. The CAMS reanalysis is a dataset that can be used to compute climatologies, study trends, evaluate models, benchmark other reanalyses or serve as boundary conditions for regional models for past periods.
Published: 2019

12. Thermomechanical Implications of Sediment Transport for the Architecture and Evolution of Continental Rifts and Margins

Author: Marta Pérez-Gussinyé, John J. Armitage, Jason Phipps Morgan, Miguel Andrés-Martínez, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), University of London [London], and COMPASS industry consortium (Continental Margin Process Analysis, Structures and Stratigraphy) at Royal Holloway, University of London MARUM (Center for Marine Environmental Sciences), University of Bremen Royal Astronomical Society French National Research Agency (ANR)
Subjects: continental extension, [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, Rift, 010504 meteorology & atmospheric sciences, Crust, Sedimentation, Geodynamics, erosion, 010502 geochemistry & geophysics, 01 natural sciences, passive margins, Geophysics, 13. Climate action, Geochemistry and Petrology, Lithosphere, Passive margin, Erosion, geodynamics, sedimentation, thermal blanketing, Petrology, surface processes, Sediment transport, Geology, 0105 earth and related environmental sciences
Abstract: International audience; Erosion and deposition redistribute mass as a continental rift evolves, which modifies crustal loads and influences subsequent deformation. Surface processes therefore impact both the architecture and the evolution of passive margins. Here we use coupled numerical models to explore the interactions between the surface, crust, and lithosphere. This interaction is primarily sensitive to the efficiency of the surface processes in transporting mass from source to sink. If transport is efficient, there are two possible outcomes: (1) Faulting within the zone of extension is longer lived and has larger offsets. This implies a reduction of the number of faults and the width of the proximal domain. (2) Efficient transport of sediment leads to significant deposition and hence thermal blanketing. This will induce a switch from brittle to ductile deformation of the upper crust in the distal domains. The feedbacks between these two outcomes depend on the extension history, the underlying lithospheric rheology, and the influence of submarine deposition on sediment transport. High erosion/sedimentation during early faulting leads to abrupt crustal necking, while intermediate syntectonic sedimentation rates over distal deep submarine hotter crust leads to unstructured wide distal domains. In models where rheological conditions favor the formation of asymmetric conjugate margins, only subaerial transport of sediments into the distal domains can increase conjugate symmetry by plastic localization. These models suggest that passive margin architecture can be strongly shaped by the solid Earth structure, sea level, and climatic conditions during breakup.
Published: 2019

13. Shallow forearc mantle dynamics and geochemistry: New insights from IODP Expedition 366

Author: Roy E. Price, Baptiste Debret, Helen M. Williams, Elmar Albers, Jaime D. Barnes, B. Walter, David P. Gillikin, Hugues Beunon, Nadine Mattielli, Sébastien P. Facq, Apollo - University of Cambridge Repository, Laboratoire Géochimie, Traçage Isotopique, Minéral et élémentaire - G-Time (Bruxelles, Belgium), Department of Earth Sciences [Cambridge, UK], University of Cambridge [UK] (CAM), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, GeoRessources, Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), School of Marine and Atmospheric Sciences [Stony Brook] (SoMAS), Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Jackson School of Geosciences (JSG), University of Texas at Austin [Austin], Union College, UK Research & Innovation (UKRI)Natural Environment Research Council (NERC), National Science Foundation (NSF), U.S. Science Support Program (USSSP) post-expedition activity (PEA), IODP-France, German Research Foundation, Special Priority Program 527 (IODP/ODP), Fonds de la Recherche Scientifique - FNRS, Fondation Wiener Anspach, and European Project: 306655,EC:FP7:ERC,ERC-2012-StG_20111012,HABITABLEPLANET(2013)
Subjects: 010504 meteorology & atmospheric sciences, Metamorphic rock, Dynamic, Geochemistry, Expedition 366, 010502 geochemistry & geophysics, 01 natural sciences, Mantle (geology), Geochemistry and Petrology, Ultramafic rock, Serpentinites, Subduction zones, 14. Life underwater, Forearc, Phase transition, 0105 earth and related environmental sciences, Peridotite, Subduction, Géochimie, Pétrologie, Geology, Mariana Convergent Margin, [SDU]Sciences of the Universe [physics], 13. Climate action, Mariana Trench, Primitive mantle
Abstract: The Mariana forearc is a unique setting on Earth where serpentinite mud volcanoes exhume clasts originating from depths of 15 km and more from the forearc mantle. These peridotite clasts are variably serpentinized by interaction with slab derived fluid, and provide a record of forearc mantle dynamics and changes in geochemistry with depth. During International Oceanic Discovery Program (IODP) Expedition 366, we recovered serpentinized ultramafic clasts contained within serpentinite muds of three different mud volcanoes located at increasing distance from the Mariana trench and at increasing depth to the slab/mantle interface: Yinazao (distance to the trench: 55 km / depth to the slab/mantle interface: 13 km), Fantangisña (62 km / 14 km) and Asùt Tesoru (72 km / 18 km). Four different types of ultramafic clasts were recovered: blue serpentinites, lizardite-serpentinites, antigorite/lizardite- and antigorite-serpentinites. Lizardite-serpentinites are primarily composed of orange serpentine, forming mesh and bastite textures. Raman and microprobe analyses revealed that these textures contain a mixture of Fe-rich brucite (XMg ~ 0.84) and lizardite/chrysotile. Antigorite/lizardite- and antigorite-serpentinites record the progressive recrystallization of mesh and bastite textures to antigorite, magnetite and pure Fe-poor brucite (XMg ~ 0.92). Oxygen isotope compositions of clasts and pore fluids showed that the transition from lizardite to antigorite is due to the increase in temperature from 200 °C to about 400 °C within the forearc area above the slab/mantle interface. Lizardite-, antigorite/lizardite- and antigorite-serpentinites displayed U-shaped chondrite normalized Rare Earth Element (REE) patterns and are characterized by high fluid mobile element concentrations (Cs, Li, Sr, As, Sb, B, Li) relative to abyssal peridotites and/or primitive mantle. The recrystallization of lizardite to antigorite is accompanied by a decrease in Cs, Li and Sr, and an increase in As and Sb concentrations in the bulk clasts, whereas B concentrations are relatively constant. Some clasts are overprinted by blue serpentine, often in association with sulfides. Most of these blue serpentinites were recovered at Yinazao and the uppermost units of Fantangisña and Asùt Tesoru suggesting alteration in the shallower portions of the forearc, possibly during exhumation of the clasts. This episode of alteration resulted in a flattening of REE spectra and an increase of Zn concentrations in serpentinites. Otherwise, no systematic changes of ultramafic clasts chemistry or mineralogy were observed with increasing depth to the slab. The samples document previously undescribed prograde metamorphic events in the shallow portions of the Mariana subduction zone, consistent with a continuous burial of the serpentinized forearc mantle during subduction. Similar processes, induced by the interaction with fluids released from the downgoing slab, likely occur in subduction zones worldwide. At greater depth, breakdown of brucite and antigorite will result in the massive transfer of fluids and fluid mobile elements, such as As, Sb and B, to the source of arc magmas., SCOPUS: ar.j, info:eu-repo/semantics/published
Published: 2019

14. COVID‐19 Crisis Reduces Free Tropospheric Ozone Across the Northern Hemisphere

Author: Marc Allaart, Susan E. Strahan, Ryan M. Stauffer, Richard Querel, Anne M. Thompson, Nicholas B. Jones, Clare Paton-Walsh, Patrick Cullis, Tatsumi Nakano, Bryan J. Johnson, Gérard Ancellet, Thomas Blumenstock, Ankie Piters, Holger Deckelmann, Omaira García, Matthias Palm, Roeland Van Malderen, Kai-Lan Chang, Nis Jepsen, Antje Inness, M.B. Tully, Ralf Sussmann, Amelie N. Röhling, Gonzague Romanens, Dagmar Kubistin, Ana Diaz Rodriguez, Fernando Chouza, René Stübi, Owen R. Cooper, Emmanuel Mahieu, Kimberly Strong, Christian Plass-Dülmer, Jonathan Davies, Richard Engelen, Peter Oelsner, David W. Tarasick, Peter von der Gathen, Jose-Luis Hernandez, Michael Gill, Justus Notholt, Thierry Leblanc, Christian Servais, Irina Petropavlovskikh, Matthias Schneider, Norrie Lyall, Rigel Kivi, Carlos Torres, Shoma Yamanouchi, Sophie Godin-Beekmann, Bogumil Kois, James W. Hannigan, Wolfgang Steinbrecht, Andy Delcloo, Deutscher Wetterdienst [Offenbach] (DWD), Environment and Climate Change Canada, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Danish Meteorological Institute (DMI), Finnish Meteorological Institute (FMI), Met Office Lerwick, Universität Bremen, Institute of Meteorology and Water Management - National Research Institute (IMGW - PIB), Royal Netherlands Meteorological Institute (KNMI), Irish Meteorological Service (MET ÉIREANN), Institut Royal Météorologique de Belgique [Bruxelles] (IRM), Institut für Meteorologie und Klimaforschung - Atmosphärische Umweltforschung (IMK-IFU), Karlsruher Institut für Technologie (KIT), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Federal Office of Meteorology and Climatology MeteoSwiss, TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), STRATO - LATMOS, University of Toronto, ESRL Global Monitoring Laboratory [Boulder] (GML), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), National Center for Atmospheric Research [Boulder] (NCAR), Agencia Estatal de Meteorología (AEMet), Meteorological Research Institute [Tsukuba] (MRI), Japan Meteorological Agency (JMA), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Institut für Meteorologie und Klimaforschung - Atmosphärische Spurengase und Fernerkundung (IMK-ASF), Australian Bureau of Meteorology [Melbourne] (BoM), Australian Government, University of Wollongong [Australia], National Institute of Water and Atmospheric Research [Lauder] (NIWA), GSFC Earth Sciences Division, NASA Goddard Space Flight Center (GSFC), Earth Science System Interdisciplinary Center [College Park] (ESSIC), College of Computer, Mathematical, and Natural Sciences [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System-University of Maryland [College Park], University of Maryland System-University of Maryland System, European Centre for Medium-Range Weather Forecasts (ECMWF), NOAA Chemical Sciences Laboratory (CSL), National Oceanic and Atmospheric Administration (NOAA), University of Wollongong, GFSC Earth Sciences Division, Kubistin, Dagmar, 1 Deutscher Wetterdienst Hohenpeißenberg Germany, Plass‐Dülmer, Christian, Davies, Jonathan, 2 Environment and Climate Change Canada Toronto ONT Canada, Tarasick, David W., Gathen, Peter von der, 3 Alfred Wegener Institut Helmholtz‐Zentrum für Polar‐ und Meeresforschung Potsdam Germany, Deckelmann, Holger, Jepsen, Nis, 4 Danish Meteorological Institute Copenhagen Denmark, Kivi, Rigel, 5 Finnish Meteorological Institute Sodankylä Finland, Lyall, Norrie, 6 British Meteorological Service Lerwick UK, Palm, Matthias, 7 University of Bremen Bremen Germany, Notholt, Justus, Kois, Bogumil, 8 Institute of Meteorology and Water Management Legionowo Poland, Oelsner, Peter, 9 Deutscher Wetterdienst Lindenberg Germany, Allaart, Marc, 10 Royal Netherlands Meteorological Institute DeBilt The Netherlands, Piters, Ankie, Gill, Michael, 11 Met Éireann (Irish Met. Service) Valentia Ireland, Van Malderen, Roeland, 12 Royal Meteorological Institute of Belgium Uccle Belgium, Delcloo, Andy W., Sussmann, Ralf, 13 Karlsruhe Institute of Technology IMK‐IFU Garmisch‐Partenkirchen Germany, Mahieu, Emmanuel, 14 Institute of Astrophysics and Geophysics University of Liège Liège Belgium, Servais, Christian, Romanens, Gonzague, 15 Federal Office of Meteorology and Climatology MeteoSwiss Payerne Switzerland, Stübi, Rene, Ancellet, Gerard, 16 LATMOS Sorbonne Université‐UVSQ‐CNRS/INSU Paris France, Godin‐Beekmann, Sophie, Yamanouchi, Shoma, 17 University of Toronto Toronto ONT Canada, Strong, Kimberly, Johnson, Bryan, 18 NOAA ESRL Global Monitoring Laboratory Boulder CO USA, Cullis, Patrick, Petropavlovskikh, Irina, Hannigan, James W., 20 National Center for Atmospheric Research Boulder CO USA, Hernandez, Jose‐Luis, 21 State Meteorological Agency (AEMET) Madrid Spain, Diaz Rodriguez, Ana, Nakano, Tatsumi, 22 Meteorological Research Institute Tsukuba Japan, Chouza, Fernando, 23 Jet Propulsion Laboratory California Institute of Technology Table Mountain Facility Wrightwood CA USA, Leblanc, Thierry, Torres, Carlos, 24 Izaña Atmospheric Research Center AEMET Tenerife Spain, Garcia, Omaira, Röhling, Amelie N., 25 Karlsruhe Institute of Technology IMK‐ASF Karlsruhe Germany, Schneider, Matthias, Blumenstock, Thomas, Tully, Matt, 26 Bureau of Meteorology Melbourne Australia, Paton‐Walsh, Clare, 27 Centre for Atmospheric Chemistry University of Wollongong Wollongong Australia, Jones, Nicholas, Querel, Richard, 28 National Institute of Water and Atmospheric Research Lauder New Zealand, Strahan, Susan, 29 NASA Goddard Space Flight Center Earth Sciences Division Greenbelt MD USA, Stauffer, Ryan M., Thompson, Anne M., Inness, Antje, 32 European Centre for Medium‐Range Weather Forecasts Reading UK, Engelen, Richard, Chang, Kai‐Lan, 19 Cooperative Institute for Research in Environmental Sciences (CIRES) University of Colorado Boulder CO USA, and Cooper, Owen R.
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Pollution: Urban, Regional and Global, Atmospheric Composition and Structure, Biogeosciences, 010502 geochemistry & geophysics, Atmospheric sciences, [SDV.MHEP.PSR]Life Sciences [q-bio]/Human health and pathology/Pulmonology and respiratory tract, 01 natural sciences, Biogeochemical Kinetics and Reaction Modeling, LIDAR, Troposphere, Oceanography: Biological and Chemical, chemistry.chemical_compound, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Emission reductions, ddc:550, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, VERTICAL-DISTRIBUTION, Marine Pollution, RECORD, NOX, 551.51, Biogeochemistry, Ozone depletion, Oceanography: General, Pollution: Urban and Regional, Geophysics, Free troposphere, Emissions, Troposphere: Composition and Chemistry, The COVID‐19 pandemic: linking health, society and environment, Cryosphere, Biogeochemical Cycles, Processes, and Modeling, Ozone, Megacities and Urban Environment, URBAN, Atmosphere, Paleoceanography, Altitude, COVID‐19, Research Letter, Global Change, Tropospheric ozone, Stratosphere, Urban Systems, 0105 earth and related environmental sciences, Aerosols, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], emissions, Northern Hemisphere, COVID-19, PROFILES, Aerosols and Particles, TRENDS, Earth sciences, ozone, Physics and Astronomy, troposphere, chemistry, 13. Climate action, General Earth and Planetary Sciences, Environmental science, Natural Hazards
Abstract: Throughout spring and summer 2020, ozone stations in the northern extratropics recorded unusually low ozone in the free troposphere. From April to August, and from 1 to 8 kilometers altitude, ozone was on average 7% (≈4 nmol/mol) below the 2000–2020 climatological mean. Such low ozone, over several months, and at so many stations, has not been observed in any previous year since at least 2000. Atmospheric composition analyses from the Copernicus Atmosphere Monitoring Service and simulations from the NASA GMI model indicate that the large 2020 springtime ozone depletion in the Arctic stratosphere contributed less than one‐quarter of the observed tropospheric anomaly. The observed anomaly is consistent with recent chemistry‐climate model simulations, which assume emissions reductions similar to those caused by the COVID‐19 crisis. COVID‐19 related emissions reductions appear to be the major cause for the observed reduced free tropospheric ozone in 2020., Plain Language Summary: Worldwide actions to contain the COVID‐19 virus have closed factories, grounded airplanes, and have generally reduced travel and transportation. Less fuel was burnt, and less exhaust was emitted into the atmosphere. Due to these measures, the concentration of nitrogen oxides and volatile organic compounds (VOCs) decreased in the atmosphere. These substances are important for photochemical production and destruction of ozone in the atmosphere. In clean or mildly polluted air, reducing nitrogen oxides and/or VOCs will reduce the photochemical production of ozone and result in less ozone. In heavily polluted air, in contrast, reducing nitrogen oxides can increase ozone concentrations, because less nitrogen oxide is available to destroy ozone. In this study, we use data from three types of ozone instruments, but mostly from ozonesondes on weather balloons. The sondes fly from the ground up to 30 kilometers altitude. In the first 8 km, we find significantly reduced ozone concentrations in the northern extratropics during spring and summer of 2020, less than in any other year since at least 2000. We suggest that reduced emissions due to the COVID‐19 crisis have lowered photochemical ozone production and have caused the observed ozone reductions in the troposphere., Key Points: In spring and summer 2020, stations in the northern extratropics report on average 7% (4 nmol/mol) less tropospheric ozone than normal Such low tropospheric ozone, over several months, and at so many sites, has not been observed in any previous year since at least 2000 Most of the reduction in tropospheric ozone in 2020 is likely due to emissions reductions related to the COVID‐19 pandemic, NASA | Earth Sciences Division (NASA Earth Science Division) http://dx.doi.org/10.13039/100014573, Gouvernement du Canada | Natural Sciences and Engineering Research Council of Canada (NSERC) http://dx.doi.org/10.13039/501100000038, Australian Research Council, Fonds De La Recherche Scientifique ‐ FNRS (FNRS) http://dx.doi.org/10.13039/501100002661, Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659, Bundesministerium für Wirtschaft und Energie (BMWi) http://dx.doi.org/10.13039/501100006360
Published: 2021

15. Temperature change in subtropical southeastern Africa during the past 790,000 yr

Author: Lynne J. Quick, Lydie M Dupont, Thomas C. Johnson, Brian M. Chase, Manuel Chevalier, Université de Lausanne (UNIL), Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226, Nelson Mandela Metropolitan University [Port Elizabeth, South Africa], Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, GSFC Astrophysics Science Division, NASA Goddard Space Flight Center (GSFC), European Project: 258657,EC:FP7:ERC,ERC-2010-StG_20091028,HYRAX(2010), Université de Lausanne = University of Lausanne (UNIL), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), and Nelson Mandela University [Port Elizabeth]
Subjects: 010506 paleontology, 010504 meteorology & atmospheric sciences, Pleistocene, [SDE.MCG]Environmental Sciences/Global Changes, Geology, Subtropics, 15. Life on land, medicine.disease_cause, 01 natural sciences, Latitude, 13. Climate action, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Climatology, Pollen, Interglacial, medicine, Crest, Glacial period, Precipitation, 0105 earth and related environmental sciences
Abstract: Across the glacial-interglacial cycles of the late Pleistocene (∼700 k.y.), temperature variability at low latitudes is often considered to have been negligible compared to changes in precipitation. However, a paucity of quantified temperature records makes this difficult to reliably assess. In this study, we used the Bayesian method CREST (Climate REconstruction SofTware) to produce a 790,000 yr quantified temperature reconstruction from a marine pollen record from southeast Africa. The results reveal a strong similarity between temperature variability in subtropical Africa and global ice volume and CO2 concentrations, indicating that temperature in the region was not controlled by local insolation, but followed global trends at these time scales, with an amplitude of ∼4 °C between glacial minima and interglacial maxima. The data also enabled us to make an assessment of the impact of temperature change on pollen diversity, with results showing there is no link between glacial-age temperatures/CO2 and a loss of diversity in this record.
Published: 2021

16. Origin of manganese in nannofossil calcite based on synchrotron nanoXRF and Xanes

Author: Isabelle Daniel, Alexandre Simionovici, Karl-Heinz Baumann, Fabienne Giraud, Marie-Pierre Aubry, Baptiste Suchéras-Marx, Camille Rivard, Luc Beaufort, Rémi Tucoulou, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Rutgers University System (Rutgers), Fachbereich Geowissenschaften [Bremen], Universität Bremen, Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Grenoble Alpes (UGA)-Université Gustave Eiffel-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)
Subjects: Calcite, 010504 meteorology & atmospheric sciences, biology, Paleontology, chemistry.chemical_element, Mineralogy, Manganese, 010502 geochemistry & geophysics, Oceanography, biology.organism_classification, 01 natural sciences, Deep sea, Incertae sedis, XANES, Diagenesis, Foraminifera, chemistry.chemical_compound, chemistry, 13. Climate action, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, 14. Life underwater, [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology, Calcareous, Geology, 0105 earth and related environmental sciences
Abstract: Calcareous nannofossils are micrometric calcite platelets secreted by the photosynthetic algae named coccolithophores and incertae sedis. Calcareous nannoplankton inhabit the photic zone from coast to open-ocean and have left an abundant fossil record since the Triassic. Therefore, they constitute an interesting material for geochemical studies although they have been overlooked in comparison to foraminifera. We have analyzed manganese distribution and valence in six calcareous nannofossil species representing different ages (Recent to Jurassic) and geological settings (land sections and deep ocean core-tops) and with different structures to assess the potential of Mn as a paleobiological or paleoenvironmental proxy. Nano x -Ray Fluorescence ( xrf ) maps were established at the esrf id 22 ni and id 21 beamlines and Mn k -edge x -Ray Absorption Near Edge Structure ( xanes ) at id 21. Mn is more abundant in nannofossils from pre-Quaternary rock samples than from core-top samples. In nannofossil rock samples, Mn nano xrf maps show distributions correlated with primary crystalline organization whereas in nannofossil core-top samples, Mn is either absent or does not follow the crystal organization. X anes analyses show that Mn is in the form of MnCO3. All these observations argue for Mn incorporation within calcareous nannofossils controlled by diagenesis through overgrowth of secondary calcite (Ca, Mn)CO3. Crusts grew along the original crystal growth directions. The incorporation of Mn in some core-top samples highlights potential early diagenesis input when the detached platelet lies on the seafloor or is still in the water column. Mn should therefore be considered a critical tool to identify diagenetic overgrowth rather than primary environmental conditions.
Published: 2021

17. Eastern Atlantic deep-water circulation and carbon storage inferred from neodymium and carbon isotopic compositions over the past 1.1 million years

Author: Charlotte Skonieczny, William Rapuc, Thomas Westerhold, Pierre Deschamps, Quentin Dubois-Dauphin, Torsten Bickert, Abel Guihou, José N. Pérez-Asensio, Kazuyo Tachikawa, Laurence Vidal, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Environnements, Dynamiques et Territoires de Montagne (EDYTEM), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), and Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])
Subjects: Marine isotope stage, 010506 paleontology, Archeology, 010504 meteorology & atmospheric sciences, Iron fertilization, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 01 natural sciences, Ocean circulation, Sea ice, Cryosphere, 14. Life underwater, Glacial period, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Global and Planetary Change, geography, geography.geographical_feature_category, Nd isotopic composition, Ocean current, Geology, Benthic foraminiferal delta C-13, Oceanography, 13. Climate action, Interglacial, Atlantic ocean, Ice sheet, Mid-Pleistocene transition
Abstract: International audience; The Mid-Pleistocene transition (MPT; 1200 to 800 thousand years, kyr) is marked by the shift from 41-kyr to 100-kyr interglacial-glacial cyclicity without substantial change in the astronomical forcing. This change in climate response relied on internal feedback processes including interaction between ice sheet/sea ice, ocean circulation and the carbon cycle. It was suggested that a major perturbation of global oceanic carbon chemistry occurred at around 900 ka (Marine Isotope Stage, MIS, 24-22) although the mechanism responsible for the change is still to be elucidated. To investigate the link between the Atlantic Meridional Overturning Circulation (AMOC) and oceanic carbon storage for the past 1100 kyr, we combined neodymium isotopic composition (Nd-143/Nd-144 or epsilon(Nd)) recorded in foraminiferal authigenic fractions with epibenthic foraminiferal delta C-13 and delta O-13 from two cores in the North- and South-east Atlantic Ocean. Glacial/interglacial eNd amplitude is smaller before the 900-ka event than after the event. The 900-ka event is marked by increase in seawater epsilon(Nd) at both sites. These observations are consistent with previous studies, suggesting basin-wide epsilon(Nd) changes. Combined with existing data, these new results reveal a persistent meridional gradient of seawater epsilon(Nd) in the Atlantic Ocean over the past 1100 kyr. By comparing the reconstructions with numerical modelling results, we propose that weaker AMOC and changes in Nd sources to the North Atlantic were the main reasons for the observed eNd shift at the 900-ka event in relation to the evolution of the Northern hemisphere cryosphere. The influence of enhanced Southern Ocean overturning circulation on eNd values was estimated to be minor. Seawater epsilon(Nd) and benthic delta C-13 relationship for the whole study period indicates the presence of carbon-rich glacial deep water (>3000 m) in the North and the South Atlantic, in particular at MIS 22 and 24. This suggests that, in addition to weaker AMOC, reduction of deep-water ventilation and/or air-sea exchange in the Southern Ocean could have been responsible for the observed low benthic delta C-13 values. Together with increased biological productivity due to iron fertilization in the Southern Ocean, the physical process significantly contributed to the deep Atlantic carbon storage during the 900-ka event and the subsequent glacial periods. (C) 2020 Elsevier Ltd. All rights reserved.
Published: 2021

18. Flow and sediment dynamics around structures in mangrove ecosystems—a modeling perspective

Author: Martin Zimmer, Véronique Helfer, Marine Le Minor, Lucy Gwen Gillis, Katrin Huhn, Géosciences Rennes (GR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, University of Bremen, Leibniz Centre for Tropical Marine Research (ZMT), Frida Sidik, Daniel A. Friess, Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), and Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Hydrology, Spatial scales, 010504 meteorology & atmospheric sciences, business.industry, 010604 marine biology & hydrobiology, Flow (psychology), Sediment, 15. Life on land, Sedimentation, Computational fluid dynamics, Sediment transport, 01 natural sciences, Roots, Flume, [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Numerical modeling, Environmental science, Flow dynamics, Ecosystem, Mangrove, [SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology, business, 0105 earth and related environmental sciences
Abstract: International audience; We conducted a literature review to determine the state of the art of hydro- and sediment dynamics modeling studies. We start with a brief overview about mangrove ecosystems while showing various aspects of hydro- and sediment dynamics without claiming exhaustiveness. Since mangrove structures are commonly mimicked using cylindrical stems, papers presenting flow and sedimentation patterns around cylinders are also included in this chapter. We report a significant gap of knowledge of hydrodynamics and sediment transport around mangrove structures at small spatial scales of root systems or trees, single roots or seedlings, and surface texture. To date, most studies are based on field measurements investigating sediment transport around mangrove structures, followed by investigations using flume experiments or numerical simulations. However, Computational Fluid Dynamics appears to be a method with great potential to quantify small-scale dynamics around mangrove structures and could lead to a better understanding of these ecosystems and their processes.
Published: 2021

19. New insights into large-scale trends of apparent organic matter reactivity in marine sediments and patterns of benthic carbon transformation

Author: F. S. Freitas, P. A. Pika, S. Kasten, B. B. Jørgensen, J. Rassmann, C. Rabouille, S. Thomas, H. Sass, R. D. Pancost, S. Arndt, University of Bristol [Bristol], Université libre de Bruxelles (ULB), Alfred Wegener Institute for Polar and Marine Research (AWI), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Aarhus University [Aarhus], Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Océan et Interfaces (OCEANIS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), School of Earth and Ocean Sciences [Cardiff], Cardiff University, This research has been supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (grant no. 9999.009541/2013-06)., Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: Biogeochemical cycle, 010504 meteorology & atmospheric sciences, Soil science, Context (language use), Evolution des espèces, 010502 geochemistry & geophysics, 01 natural sciences, Carbon cycle, Sedimentary depositional environment, Life, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, QH501-531, Organic matter, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, QH540-549.5, 0105 earth and related environmental sciences, Earth-Surface Processes, Total organic carbon, chemistry.chemical_classification, QE1-996.5, Ecologie, Géologie et minéralogie, Ecology, Geology, 15. Life on land, chemistry, 13. Climate action, Benthic zone, Anaerobic oxidation of methane, Environmental science, [CHIM.OTHE]Chemical Sciences/Other
Abstract: Constraining the mechanisms controlling organic matter (OM) reactivity and, thus, degradation, preservation, and burial in marine sediments across spatial and temporal scales is key to understanding carbon cycling in the past, present, and future. However, we still lack a detailed quantitative understanding of what controls OM reactivity in marine sediments and, consequently, a general framework that would allow model parametrization in data-poor areas. To fill this gap, we quantify apparent OM reactivity (i.e. OM degradation rate constants) by extracting reactive continuum model (RCM) parameters (a and v, which define the shape and scale of OM reactivity profiles, respectively) from observed benthic organic carbon and sulfate dynamics across 14 contrasting depositional settings distributed over five distinct benthic provinces. We further complement the newly derived parameter set with a compilation of 37 previously published RCM a and v estimates to explore large-scale trends in OM reactivity. Our analysis shows that the large-scale variability in apparent OM reactivity is largely driven by differences in parameter a (10-3-107) with a high frequency of values in the range 100-104 years. In contrast, and in broad agreement with previous findings, inversely determined v values fall within a narrow range (0.1-0.2). Results also show that the variability in parameter a and, thus, in apparent OM reactivity is a function of the whole depositional environment, rather than traditionally proposed, single environmental controls (e.g. water depth, sedimentation rate, OM fluxes). Thus, we caution against the simplifying use of a single environmental control for predicting apparent OM reactivity beyond a specific local environmental context (i.e. well-defined geographic scale). Additionally, model results indicate that, while OM fluxes exert a dominant control on depth-integrated OM degradation rates across most depositional environments, apparent OM reactivity becomes a dominant control in depositional environments that receive exceptionally reactive OM. Furthermore, model results show that apparent OM reactivity exerts a key control on the relative significance of OM degradation pathways, the redox zonation of the sediment, and rates of anaerobic oxidation of methane. In summary, our large-scale assessment (i) further supports the notion of apparent OM reactivity as a dynamic ecosystem property, (ii) consolidates the distributions of RCM parameters, and (iii) provides quantitative constraints on how OM reactivity governs benthic biogeochemical cycling and exchange. Therefore, it provides important global constraints on the most plausible range of RCM parameters a and v and largely alleviates the difficulty of determining OM reactivity in RCM by constraining it to only one variable, i.e. the parameter a. It thus represents an important advance for model parameterization in data-poor areas., SCOPUS: ar.j, info:eu-repo/semantics/published
Published: 2021

20. Microstructures of epidote-prehnite bearing damaged granitoids (northern Victoria Land, Antarctica): clues for the interaction between faulting and hydrothermal fluids

Author: Laura Crispini, Laura Federico, Cristina Malatesta, Benoit Ildefonse, Andreas Läufer, Frank Lisker, Department of Earth, Environmental and Life Sciences (DISTAV), Universita degli studi di Genova, Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS), Universität Bremen, and Federal Institute for Geosciences and Natural Resources (BGR)
Subjects: 010504 meteorology & atmospheric sciences, Geochemistry, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Slip (materials science), Epidote-prehnite EBSD, Fault (geology), engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Lanterman fault-Rennick Graben fault system, chemistry.chemical_compound, Chlorite, 0105 earth and related environmental sciences, Calcite, geography, geography.geographical_feature_category, Fault reactivation, Geology, Crust, Epidote, Damage zones, Damage zones, Syntectonic hydrothermal alteration, Epidote-prehnite EBSD, Fault reactivation, Lanterman fault-Rennick Graben fault system, Antarctica, Graben, Prehnite, chemistry, 13. Climate action, engineering, Syntectonic hydrothermal alteration, Antarctica
Abstract: International audience; Exhumed faults in granitoids along the Lanterman Fault-Rennick Graben Fault system (northern Victoria Land, Antarctica) show superposed ductile to brittle deformation and pervasive hydrothermal fluid-rock interaction. These processes triggered multiple brittle slip events producing crosscutting epidote and prehnite-rich fault veins, ultracataclasites and pseudotachylytes of crushing origin. Combined microstructural and minerochemical investigations on fault damage zones show three types of alteration: (i) albitization of K-feldspar and Caplagioclase; (ii) crystallization of prehnite and calcite in veins; (iii) alteration of magmatic phases by secondary hydrous minerals (e.g. chlorite, white mica, epidote and prehnite). The fault experienced various episodes of strain weakening and hardening, due to alteration of minerals and precipitation of epidote and prehnite within ultracataclastic intervals, at decreasing temperature conditions (200 < T • C < 450) and varying CO 2 fugacity of the fluids. Cyclic crystallization of epidote/prehnite within the fault cores caused cementation and locking of faults, concentration of deformation at weaker horizons and a progressive broadening of the fault zone. Our results indicate that multiple co-seismic slip and syntectonic fluid flow very likely occurred prior to the Cenozoic brittle reactivation of inherited anisotropies in the northern Victoria Land crust along the Lanterman Fault-Rennick Graben Fault system and underlines its high potential for polyphasicity.
Published: 2021

21. A global database of Holocene paleotemperature records

Author: Marcela Sandra Tonello, Vincent Montade, Walter Finsinger, Karen J. Taylor, Manuel Chevalier, Isabelle Larocque-Tobler, Philipp Sommer, Nicholas P. McKay, Mateusz Płóciennik, Snezhana Zhilich, David F. Porinchu, Andrei Andreev, Markus Heinrichs, Tomi P. Luoto, Elena A. Ilyashuk, Anson W. Mackay, Deborah Khider, Stephen J. Roberts, Cody C. Routson, Les C. Cwynar, Samuel L Jaccard, Naomi Holmes, Kira Rehfeld, Aaron P. Potito, Emma J. Pearson, Steve Juggins, Anais Orsi, Louise C. Foster, Angela Self, Sakari Salonen, Basil A. S. Davis, Boris K. Biskaborn, Christoph Dätwyler, Sebastien Bertrand, Anne de Vernal, Jeannine Marie St-Jacques, Angelica Feurdean, Janet M. Wilmshurst, Lukas Jonkers, Heikki Seppä, Stephen J. Brooks, Elizabeth K. Thomas, Sonja Hausmann, Peter G. Langdon, Steven B. Malevich, Larisa Nazarova, Shyhrete Shala, Enikö Magyari, Matthew Peros, Scott A. Reinemann, Krystyna M. Saunders, Elena Novenko, Barbara Stenni, Yarrow Axford, Liudmila Syrykh, Julien Emile-Geay, Nicolas Rolland, Bryan G. Mark, Jianyong Li, Andria Dawson, Mathew Fox, André F. Lotter, Jessica E. Tierney, Oliver Heiri, Stefan Engels, Ian R. Walker, Andrew P. Rees, Pol Tarrats, Valerie van den Bos, Konrad Gajewski, Brian M. Chase, Eugene R. Wahl, Martin Grosjean, Boris P. Ilyashuk, Thomas Brussel, Mónika Tóth, Enlou Zhang, Darrell S. Kaufman, Olivier Cartapanis, Magaly Caniupán, Julieta Massaferro, Reinhard Pienitz, John M. Fegyveresi, Manuel Bringué, Carrie Morrill, Gaute Velle, M. P. Erb, Marie Claude Fortin, Petr Pařil, Karin A. Koinig, Richard S. Vachula, Paola Moffa-Sanchez, Jeremiah Marsicek, Northern Arizona University [Flagstaff], Institute of Earth Surface Dynamics [Lausanne], Université de Lausanne (UNIL), Utrecht University Palaeoecology, Laboratory of Palaeobotany and Palynology (UTRECHT UNIVERSITY), Utrecht University [Utrecht], Oeschger Centre for Climate Change Research (OCCR), University of Bern, University of Arizona, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226, Mount Royal University, Centre de recherche sur la dynamique du système Terre (GEOTOP), Université de Montréal (UdeM)-McGill University = Université McGill [Montréal, Canada]-École Polytechnique de Montréal (EPM)-Concordia University [Montreal]-Université du Québec à Rimouski (UQAR)-Université du Québec à Montréal = University of Québec in Montréal (UQAM)-Université du Québec en Abitibi-Témiscamingue (UQAT), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institute of Environmental Physics [Heidelberg] (IUP), Universität Heidelberg [Heidelberg], Programme CIT, Ligue Nationale Contre le Cancer, Snecma Propulsion Solide (SPS), SAFRAN Group, University of Southern California (USC), Senckenberg biodiversität und klima forschungszentrum (BIK-F), Forschungsinstitut Senckenberg (SGN), Université d'Ottawa [Ontario] (uOttawa), Faculty of Biological and Environmental Sciences [Helsinki], University of Helsinki, Department of Environmental and Landscape Geography, Eötvös Loránd University (ELTE), MTA-MTM-ELTE Research Group for Paleontology, Eötvös Loránd University (ELTE)-Hungarian Academy of Sciences (MTA), GINOP Sustainable Ecosystem Research Group, MTA Centre for Ecological Research [Tihany], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET), Centre d'Etudes Nordiques (CEN), Université Laval [Québec] (ULaval), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Department of Geosciences and Geography [Helsinki], Falculty of Science [Helsinki], University of Helsinki-University of Helsinki, Departemanto di Scienze Ambientali Informatica e Statistica (DAIS), University of Ca’ Foscari [Venice, Italy], Uni Research Environment, Uni Research Ltd, University of Bath [Bath], Université de Lausanne = University of Lausanne (UNIL), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), École Polytechnique de Montréal (EPM)-McGill University = Université McGill [Montréal, Canada]-Université de Montréal (UdeM)-Université du Québec en Abitibi-Témiscamingue (UQAT)-Université du Québec à Rimouski (UQAR)-Concordia University [Montreal]-Université du Québec à Montréal = University of Québec in Montréal (UQAM), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Universität Heidelberg [Heidelberg] = Heidelberg University, Ligue Nationale Contre le Cancer (LNCC), Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Faculty of Biological and Environmental Sciences, and Department of Geosciences and Geography
Subjects: Peat, 010504 meteorology & atmospheric sciences, 580 Plants (Botany), computer.software_genre, 01 natural sciences, MILLENNIAL-SCALE CHANGES, Proxy (climate), purl.org/becyt/ford/1 [https], purl.org/becyt/ford/1.5 [https], INTERTROPICAL CONVERGENCE ZONE, HOLOCENE, 910 Geography & travel, lcsh:Science, Holocene, LAKE VUOLEP-NJAKAJAURE, geography.geographical_feature_category, Database, EASTERN TIBETAN PLATEAU, [SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM], Computer Science Applications, LATE-QUATERNARY VEGETATION, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, SEA-SURFACE TEMPERATURE, PROXIES, Statistics, Probability and Uncertainty, geog, Geology, Information Systems, Statistics and Probability, 1171 Geosciences, 010506 paleontology, NORTHERN NORTH-ATLANTIC, DATABASE, PALEOTEMPERATURE, [SDE.MCG]Environmental Sciences/Global Changes, education, Library and Information Sciences, Education, Paleoclimatology, SOUTH CHINA SEA, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Southern Hemisphere, 1172 Environmental sciences, POLLEN-BASED RECONSTRUCTION, 550 Earth sciences & geology, 0105 earth and related environmental sciences, geography, [INFO.INFO-DB]Computer Science [cs]/Databases [cs.DB], Intertropical Convergence Zone, Glacier, 15. Life on land, WESTERN EQUATORIAL PACIFIC, Sea surface temperature, 13. Climate action, Settore GEO/08 - Geochimica e Vulcanologia, Earth and Environmental Sciences, lcsh:Q, computer
Abstract: A comprehensive database of paleoclimate records is needed to place recent warming into the longer-term context of natural climate variability. We present a global compilation of quality-controlled, published, temperature-sensitive proxy records extending back 12,000 years through the Holocene. Data were compiled from 679 sites where time series cover at least 4000 years, are resolved at sub-millennial scale (median spacing of 400 years or finer) and have at least one age control point every 3000 years, with cut-off values slackened in data-sparse regions. The data derive from lake sediment (51%), marine sediment (31%), peat (11%), glacier ice (3%), and other natural archives. The database contains 1319 records, including 157 from the Southern Hemisphere. The multi-proxy database comprises paleotemperature time series based on ecological assemblages, as well as biophysical and geochemical indicators that reflect mean annual or seasonal temperatures, as encoded in the database. This database can be used to reconstruct the spatiotemporal evolution of Holocene temperature at global to regional scales, and is publicly available in Linked Paleo Data (LiPD) format. Fil: Kaufman, Darrell. Northern Arizona University.; Estados Unidos Fil: McKay, Nicholas. Northern Arizona University.; Estados Unidos Fil: Routson, Cody. Northern Arizona University.; Estados Unidos Fil: Erb, Michael. Northern Arizona University.; Estados Unidos Fil: Davis, Basil. University Of Lausanne; Suiza Fil: Heiri, Oliver. University Of Basel; Suiza Fil: Jaccard, Samuel. University Of Bern; Suiza Fil: Tierney, Jessica. University of Arizona; Estados Unidos Fil: Dätwyler, Christoph. University Of Bern; Suiza Fil: Axford, Yarrow. Northwestern University; Estados Unidos Fil: Brussel, Thomas. University of Utah; Estados Unidos Fil: Cartapanis, Olivier. University Of Bern; Suiza Fil: Chase, Brian. Universite de Montpellier; Francia Fil: Dawson, Andria. Mount Royal University; Canadá Fil: de Vernal, Anne. Université du Québec a Montreal; Canadá Fil: Engels, Stefan. University of London; Reino Unido Fil: Jonkers, Lukas. University Of Bremen; Alemania Fil: Marsicek, Jeremiah. University of Wisconsin-Madison; Estados Unidos Fil: Moffa Sánchez, Paola. University of Durham; Reino Unido Fil: Morrill, Carrie. University of Colorado; Estados Unidos Fil: Orsi, Anais. Université Paris-Saclay; Francia Fil: Rehfeld, Kira. Heidelberg University; Alemania Fil: Saunders, Krystyna. Australian Nuclear Science And Technology Organisation; Australia Fil: Sommer, Philipp. University Of Lausanne; Suiza Fil: Thomas, Elizabeth. University At Buffalo; Estados Unidos Fil: Tonello, Marcela Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Tóth, Mónika. Balaton Limnological Institute; Hungría Fil: Vachula, Richard. Brown University; Estados Unidos Fil: Andreev, Andrei. Alfred Wegener Institut Helmholtz Centre for Polar and Marine Research; Alemania Fil: Bertrand, Sebastien. Ghent University; Bélgica Fil: Massaferro, Julieta. Administración de Parques Nacionales. Parque Nacional "Nahuel Huapi"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Published: 2020

22. Lithospheric Strength and Rift Migration Controls on Synrift Stratigraphy and Breakup Unconformities at Rifted Margins: Examples From Numerical Models, the Atlantic and South China Sea Margins

Author: Marta Pérez-Gussinyé, Y. Xin, Miguel Andrés-Martínez, John J. Armitage, Mario Araujo, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Petrobras Research Center (CENPES), Petrobras, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences [Beijing] (CAS), IFP Energies nouvelles (IFPEN), and Southern University of Science and Technology [Shenzhen] (SUSTech)
Subjects: Rift, 010504 meteorology & atmospheric sciences, stratigraphy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Subsidence, breakup, 010502 geochemistry & geophysics, Breakup, rifting, 01 natural sciences, Unconformity, unconformity, Tectonics, Paleontology, Geophysics, Stratigraphy, Geochemistry and Petrology, Lithosphere, Passive margin, synrift architecture, 14. Life underwater, tectonic architecture, Geology, 0105 earth and related environmental sciences
Abstract: International audience; Synrift stratigraphy and the distribution of breakup-related erosional unconformities vary vastly between passive margins and cannot be explained by classical rifting models. Here we use numerical modeling to predict their spatiotemporal distribution. We show that synrift stratigraphy mimics rift architecture, which is controlled by lithospheric strength. Basinward rift migration during extension produces (1) oceanward younging, syntectonic and posttectonic sequences, (2) rift migration unconformities, RMUs, predating breakup, and (3) a breakup unconformity, BU, that only extends over the outermost margins, since breakup is not linked with a sudden stress drop. With small synrift sedimentation, the RMUs and BU laterally merge to form a margin-wide unconformity. In symmetric, wide conjugate margins, which arise for weak lithospheres such as the South China Sea, a long phase of distributed deformation with little subsidence results in early synrift sediment over most of the margins. RMUs merge into a single event that marks the subsequent focusing of deformation into a narrow breakup area, which experiences short-lived intense thinning and subsidence. In asymmetric conjugate margins, lateral rift migration transports shallowly deposited, early synrift sediments from the narrow to the wide, hyperextended margin, leading to a condensed syntectonic sequence and a single BU in the narrow margin and a series of RMUs in the wide one. For very weak lower crusts, lateral rift migration generates large synrift sag basins in the wide margin, as in Angola and Congo margins. Our models resemble the observed margins tectonic diversity and may be used as templates for interpreting their distal, unexplored areas.
Published: 2020

23. Overview: Integrative and Comprehensive Understanding on Polar Environments (iCUPE) – concept and initial results

Author: T. Petäjä, E.-M. Duplissy, K. Tabakova, J. Schmale, B. Altstädter, G. Ancellet, M. Arshinov, Y. Balin, U. Baltensperger, J. Bange, A. Beamish, B. Belan, A. Berchet, R. Bossi, W. R. L. Cairns, R. Ebinghaus, I. El Haddad, B. Ferreira-Araujo, A. Franck, L. Huang, A. Hyvärinen, A. Humbert, A.-C. Kalogridis, P. Konstantinov, A. Lampert, M. MacLeod, O. Magand, A. Mahura, L. Marelle, V. Masloboev, D. Moisseev, V. Moschos, N. Neckel, T. Onishi, S. Osterwalder, A. Ovaska, P. Paasonen, M. Panchenko, F. Pankratov, J. B. Pernov, A. Platis, O. Popovicheva, J.-C. Raut, A. Riandet, T. Sachs, R. Salvatori, R. Salzano, L. Schröder, M. Schön, V. Shevchenko, H. Skov, J. E. Sonke, A. Spolaor, V. K. Stathopoulos, M. Strahlendorff, J. L. Thomas, V. Vitale, S. Vratolis, C. Barbante, S. Chabrillat, A. Dommergue, K. Eleftheriadis, J. Heilimo, K. S. Law, A. Massling, S. M. Noe, J.-D. Paris, A. S. H. Prévôt, I. Riipinen, B. Wehner, Z. Xie, H. K. Lappalainen, Institute for Atmospheric and Earth System Research (INAR), Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Laboratory of Atmospheric Chemistry [Paul Scherrer Institute] (LAC), Paul Scherrer Institute (PSI), School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), DLR Institute of Flight Guidance, Deutsches Zentrum für Luft- und Raumfahrt [Braunschweig] (DLR), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), V.E. Zuev Institute of Atmospheric Optics (IAO), Siberian Branch of the Russian Academy of Sciences (SB RAS), Center for Applied Geoscience [Tübingen] (ZAG), Eberhard Karls Universität Tübingen = Eberhard Karls University of Tuebingen, German Research Centre for Geosciences - Helmholtz-Centre Potsdam (GFZ), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), iCLIMATE Aarhus University Interdisciplinary Centre for Climate Change, Aarhus University [Aarhus], Institute of Polar Sciences [Venezia-Mestre] (CNR-ISP), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Centre for Materials and Coastal Research [Geesthacht], Helmholtz-Zentrum Geesthacht (GKSS), Géosciences Environnement Toulouse (GET), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Climate Research Division [Toronto], Environment and Climate Change Canada, Arctic Space Centre [Helsinki], Finnish Meteorological Institute (FMI), Alfred Wegener Institute for Polar and Marine Research (AWI), Fachbereich Geowissenschaften [Bremen], Universität Bremen, MSU Faculty of Geography [Moscow], Lomonosov Moscow State University (MSU), Laboratory of Smart Technologies for Sustainable Development of Urban Environment unplder Global Change, Peoples Friendship University of Russia [RUDN University] (RUDN), Department of Environmental Science and Analytical Chemistry [Stockholm] (ACES), Stockholm University, Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Kola Science Center of Russian Academy of Sciences, D.V. Skobeltsyn Institute of Nuclear Physics (SINP), Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), GeoForschungsZentrum - Helmholtz-Zentrum Potsdam (GFZ), Institute of Atmospheric Pollution Research (IIA), P.P. Shirshov Institute of Oceanology (SIO), Russian Academy of Sciences [Moscow] (RAS), Environmental Radioactivity laboratory (ERL), Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety (INRASTES), National Center for Scientific Research 'Demokritos' (NCSR)-National Center for Scientific Research 'Demokritos' (NCSR), Institute of Agricultural and Environmental Sciences (IAES), Estonian University of Life Sciences (EMU), ICOS-RAMCES (ICOS-RAMCES), Department of Experimental Aerosol and Cloud Microphysics, Leibniz Institute for Tropospheric Research (TROPOS), This project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement no. 689443 via project iCUPE (Integrative and Comprehensive Understanding on Polar Environments) and through ACTRIS2 (654109). Additional financial support was received through the Academy of Finland (Center of Excellence in Atmospheric Sciences) under the projects PROFI-3 (decision number 311932), NANOBIOMASS (decision number 307537), and SA-MOSAiC (decision number 333397), as well as the Belmont Forum project 'Community Resilience to Boreal Environmental change: Assessing Risks from fire and disease' (ACRoBEAR, decision number 334792). Olga Popovicheva received partial support from the Russian Foundation for Basic Research (RFBR) under project no. 18-05-60084. Ground-based lidar observations in Siberia were supported in part by the Ministry of Science and Education of the Russian Federation (agreement no. 14.616.21.0104, unique identifier RFMEFI61618X0104). The French groups received support from the French Arctic Initiative project 'Pollution in the Arctic System' (PARCS). Part of this study was supported by the Danish Environmental Protection Agency and the Danish Energy Agency by means of DANCEA funds for Environmental Support to the Arctic Region. Part of this study was funded by the German Science Foundation (Deutsche Forschungsgemeinschaft, DFG) as project numbers LA 2907/5-3, BA 1988/14-3, and WI 1449/22-3. Julia Schmale holds the Ingvar Kamprad Chair, sponsored by Ferring Pharmaceuticals., European Project: 654109,H2020,H2020-INFRAIA-2014-2015,ACTRIS-2(2015), Department of Physics, Department of Agricultural Sciences, Global Atmosphere-Earth surface feedbacks, INAR Physics, Radar Meteorology group, Air quality research group, University of Helsinki, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Consiglio Nazionale delle Ricerche [Roma] (CNR), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), and Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )
Subjects: Atmospheric Science, Earth observation, SNOW-COVERED AREA, 010504 meteorology & atmospheric sciences, aerosol, Context (language use), ARCTIC AIR-POLLUTION, EURASIAN EXPERIMENT PEEX, 010501 environmental sciences, 01 natural sciences, 114 Physical sciences, lcsh:Chemistry, BOREAL FOREST, Arctic, 11. Sustainability, PARTICLE FORMATION, PERSISTENT ORGANIC POLLUTANTS, 14. Life underwater, LONG-RANGE TRANSPORT, 0105 earth and related environmental sciences, Grand Challenges, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], business.industry, Data stream mining, Environmental resource management, 15. Life on land, ATMOSPHERIC MERCURY, Natural resource, lcsh:QC1-999, Thematic map, iCUPE, climate change, SOURCE APPORTIONMENT, lcsh:QD1-999, 13. Climate action, BLACK CARBON, Environmental science, Satellite, business, lcsh:Physics
Abstract: The role of polar regions is increasing in terms ofmegatrends such as globalization, new transport routes, demography,and the use of natural resources with consequenteffects on regional and transported pollutant concentrations.We set up the ERA-PLANET Strand 4 project “iCUPE – integrativeand Comprehensive Understanding on Polar Environments”to provide novel insights and observational dataon global grand challenges with an Arctic focus. We utilizean integrated approach combining in situ observations, satelliteremote sensing Earth observations (EOs), and multi-scalemodeling to synthesize data from comprehensive long-termmeasurements, intensive campaigns, and satellites to deliverdata products, metrics, and indicators to stakeholders concerningthe environmental status, availability, and extractionof natural resources in the polar areas. The iCUPE work consistsof thematic state-of-the-art research and the provisionof novel data in atmospheric pollution, local sources andtransboundary transport, the characterization of arctic surfacesand their changes, an assessment of the concentrationsand impacts of heavy metals and persistent organic pollutantsand their cycling, the quantification of emissions from naturalresource extraction, and the validation and optimizationof satellite Earth observation (EO) data streams. In this paperwe introduce the iCUPE project and summarize initialresults arising out of the integration of comprehensive in situobservations, satellite remote sensing, and multi-scale modelingin the Arctic context.
Published: 2020

24. Particulate Organic Carbon Deconstructed: Molecular and Chemical Composition of Particulate Organic Carbon in the Ocean

Author: Gesine Mollenhauer, Barbara M. Scholz-Böttcher, Rienk H. Smittenberg, Jenan J. Kharbush, Carol Arnosti, Igor Obreht, Benjamin A. S. Van Mooy, Kevin W. Becker, Frédéric A. C. Le Moigne, Wiebke Mohr, Boris P. Koch, Hilary G. Close, Morten Hvitfeldt Iversen, Department of Earth and Environmental Sciences [Ann Arbor], University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Rosenstiel School of Marine and Atmospheric Science (RSMAS), University of Miami [Coral Gables], Woods Hole Oceanographic Institution (WHOI), Department of Marine, Earth, and Atmospheric Sciences [NCSU] (MEAS), North Carolina State University [Raleigh] (NC State), University of North Carolina System (UNC)-University of North Carolina System (UNC), Department of Geological Sciences [Stockholm], Stockholm University, Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Alfred Wegener Institute for Polar and Marine Research (AWI), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Department of Isotope Biogeochemistry, and Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ)
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, lcsh:QH1-199.5, Earth science, Ocean Engineering, organic matter characterization, Aquatic Science, lcsh:General. Including nature conservation, geographical distribution, Oceanography, 01 natural sciences, Deep sea, Carbon cycle, Water column, Phytoplankton, Organic geochemistry, 14. Life underwater, structural analysis, lcsh:Science, Chemical composition, marine particles, 0105 earth and related environmental sciences, Water Science and Technology, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Global and Planetary Change, Particulate organic carbon, marine microbes, Primary (chemistry), 010604 marine biology & hydrobiology, biomarkers, water column, Marine particles, Marine microbes, Structural analysis, Organic matter characterization, Biomarkers, 13. Climate action, phytoplankton, Environmental science, lcsh:Q
Abstract: International audience; The dynamics of the particulate organic carbon (POC) pool in the ocean are central to the marine carbon cycle. POC is the link between surface primary production, the deep ocean, and sediments. The rate at which POC is degraded in the dark ocean can impact atmospheric CO 2 concentration. Therefore, a central focus of marine organic geochemistry studies is to improve our understanding of POC distribution, composition, and cycling. The last few decades have seen improvements in analytical techniques that have greatly expanded what we can measure, both in terms of organic compound structural diversity and isotopic composition, and complementary molecular omics studies. Here we provide a brief overview of the autochthonous, allochthonous, and anthropogenic components comprising POC in the ocean. In addition, we highlight key needs for future research that will enable us to more effectively connect diverse data sources and link the identity and structural diversity of POC to its sources and transformation processes.
Published: 2020

25. Deglacial upslope shift of NE Atlantic intermediate waters controlled slope erosion and cold-water coral mound formation (Porcupine Seabight, Irish margin)

Author: Dierk Hebbeln, Markus Hermann Eisele, Anne Kremer, Claudia Wienberg, Jürgen Titschack, Norbert Frank, Jan Fietzke, Ricardo De Pol-Holz, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Institute of Environmental Physics [Heidelberg] (IUP), Universität Heidelberg [Heidelberg] = Heidelberg University, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Géochrononologie Traceurs Archéométrie (GEOTRAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), GAIA-Antártica, Universidad de Magallanes (UMAG), Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Universität Heidelberg [Heidelberg], Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010506 paleontology, Archeology, Global and Planetary Change, 010504 meteorology & atmospheric sciences, biology, Coral, Sediment, Geology, Sedimentation, biology.organism_classification, 01 natural sciences, Oceanography, Transition zone, Erosion, Deglaciation, Belgica, 14. Life underwater, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Ecology, Evolution, Behavior and Systematics, Holocene, 0105 earth and related environmental sciences
Abstract: Highlights • Holocene cold-water coral mound formation started non-synchronous in Belgica province. • Coral mounds and slope sediments record changes in intermediate water mass dynamics. • Increased turbulent bottom currents steered slope erosion and mound formation. • Internal waves at the ENAW-MOW boundary enhance energy supply and particle flux. • Transition zone between the ENAW-MOW shifted 250 m upslope during the last deglacial. Abstract Turbulent bottom currents significantly influence the formation of cold-water coral mounds and sedimentation processes on continental slopes. Combining records from coral mounds and adjacent slope sediments therefore provide an unprecedented palaeo-archive to understand past variations of intermediate water-mass dynamics. Here, we present coral ages from coral mounds of the Belgica province (Porcupine Seabight, NE Atlantic), which indicate a non-synchronous Holocene re-activation in mound formation suggested by a temporal offset of ∼2.7 kyr between the deep (start: ∼11.3 ka BP at 950 m depth) and shallow (start: ∼8.6 ka BP at 700 m depth) mounds. A similar depth-dependent pattern is revealed in the slope sediments close to these mounds that become progressively younger from 22.1 ka BP at 990 m to 12.2 ka BP at 740 m depth (based on core-top ages). We suggest that the observed changes are the consequence of enhanced bottom-water hydrodynamics, caused by internal waves associated to the re-invigoration of the Mediterranean Outflow Water (MOW) and the development of a transition zone (TZ) between the MOW and the overlying Eastern North Atlantic Water (ENAW), which established during the last deglacial. These highly energetic conditions induced erosion adjacent to the Belgica mounds and supported the re-initiation of mound formation by increasing food and sediment fluxes. The striking depth-dependent patterns are likely linked to a shift of the ENAW-MOW-TZ, moving the level of maximum energy ∼250 m upslope since the onset of the last deglaciation.
Published: 2020

26. Mariana serpentinite mud volcanism exhumes subducted seamount materials: implications for the origin of life

Author: R.T. Kevorkian, Barbara A. Bekins, Jeffrey G. Ryan, Shino Suzuki, Kevin T. M. Johnson, Roy E. Price, Walter Kurz, P. Eickenbusch, Diva J. Amon, Rui Zhang, Elmar Albers, Shirley A. Pomponi, John W. Shervais, S.S. Mantovanelli, C. Geoffrey Wheat, Jianghong Deng, Deborah Glickson, R.M. Johnston, Baptiste Debret, Emanuelle Frery, Jung-Woo Park, Katsuyoshi Michibayashi, B. Walter, Patricia Fryer, Olivier Sissmann, K.K. Mullane, Christopher Kelley, Yanhui Dong, Vitor Magalhães, Yuji Ichiyama, Ken Takai, Trevor Williams, C. D. Menzies, Craig L. Moyer, Walter Menapace, School of Ocean and Earth Science and Technology (SOEST), University of Hawai‘i [Mānoa] (UHM), University of Alaska [Fairbanks] (UAF), International Ocean Discovery Program, School of Geosciences, University of South Florida, Florida, Tampa, USA, University of South Florida [Tampa] (USF), NAWI Graz Geocentre, Karl-Franzens-Universität [Graz, Autriche], Utah State University (USU), University of Bremen, United States Geological Survey (USGS), University of Cambridge [UK] (CAM), School of Earth and Space Sciences [Hefei], University of Science and Technology of China [Hefei] (USTC), Second Institute of Oceanography, State Oceanic Administration (SOA), Department of Environmental Systems Science [ETH Zürich] (D-USYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), CSIRO Division of Petroleum Resources, Kensington, Australia, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Department of Earth Sciences [Chiba], Chiba University, The University of Tennessee [Knoxville], Instituto Português de Investigação do Mar e da Atmosfera (IPMA), Oceanographic Institute, Univesidade de Sao Paulo, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, National Oceanography Centre [Southampton] (NOC), University of Southampton, Graduate School of Environmental Studies [Nagoya], Nagoya University, Western Washington University (WWU), Scripps Institution of Oceanography (SIO), University of California [San Diego] (UC San Diego), University of California-University of California, School of Earth and Environmental Sciences [Seoul] (SEES), Seoul National University [Seoul] (SNU), State University of New York (SUNY), IFP Energies nouvelles (IFPEN), Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), GeoRessources, Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Institut national des sciences de l'Univers (INSU - CNRS), State Key Laboratory of Marine Environmental Science (Xiamen University), The Natural History Museum [London] (NHM), National Academy of Sciences Washington, Harbor Branch Oceanographic Institute [Fort Pierce], and Florida Atlantic University [Boca Raton]
Subjects: geology, Mariana trench, Serpentinite mud volcanism, Subducted cretaceous seamounts, Exhumed microbes, Evolution of life, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], General Mathematics, Seamount, Origin of Life, Geochemistry, astrobiology, General Physics and Astronomy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Volcanism, Volcanic Eruptions, 010502 geochemistry & geophysics, 01 natural sciences, volcanology, Abiogenesis, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, evolution of life, Convergent boundary, Seawater, 14. Life underwater, 0105 earth and related environmental sciences, geochemistry, geography, Minerals, geography.geographical_feature_category, Subduction, exhumed microbes, General Engineering, Articles, serpentinite mud volcanism, subducted cretaceous seamounts, 13. Climate action, plate tectonics, Mariana Trench, Ridge (meteorology), Geology, Research Article
Abstract: The subduction of seamounts and ridge features at convergent plate boundaries plays an important role in the deformation of the overriding plate and influences geochemical cycling and associated biological processes. Active serpentinization of forearc mantle and serpentinite mud volcanism on the Mariana forearc (between the trench and active volcanic arc) provides windows on subduction processes. Here, we present (1) the first observation of an extensive exposure of an undeformed Cretaceous seamount currently being subducted at the Mariana Trench inner slope; (2) vertical deformation of the forearc region related to subduction of Pacific Plate seamounts and thickened crust; (3) recovered Ocean Drilling Program and International Ocean Discovery Program cores of serpentinite mudflows that confirm exhumation of various Pacific Plate lithologies, including subducted reef limestone; (4) petrologic, geochemical and paleontological data from the cores that show that Pacific Plate seamount exhumation covers greater spatial and temporal extents; (5) the inference that microbial communities associated with serpentinite mud volcanism may also be exhumed from the subducted plate seafloor and/or seamounts; and (6) the implications for effects of these processes with regard to evolution of life. This article is part of a discussion meeting issue ‘Serpentine in the Earth system’.
Published: 2020

27. Analytical and Computational Advances, Opportunities, and Challenges in Marine Organic Biogeochemistry in an Era of 'Omics'

Author: Andrew D. Steen, Stephanie Kusch, Hussain A. Abdulla, Nevenka Cakić, Sarah Coffinet, Thorsten Dittmar, James M. Fulton, Valier Galy, Kai-Uwe Hinrichs, Anitra E. Ingalls, Boris P. Koch, Elizabeth Kujawinski, Zhanfei Liu, Helena Osterholz, Darci Rush, Michael Seidel, Julio Sepúlveda, Stuart G. Wakeham, The University of Tennessee [Knoxville], Universität zu Köln, Texas A&M University [Corpus Christi], Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Carl Von Ossietzky Universität Oldenburg, Baylor University, Woods Hole Oceanographic Institution (WHOI), University of Washington [Seattle], Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), University of Texas at Austin [Austin], Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Royal Netherlands Institute for Sea Research (NIOZ), Utrecht University [Utrecht], Institute of Arctic and Alpine Research (INSTAAR), University of Colorado [Boulder], Deutsche Forschungsgemeinschaft, project number: 422798570, and The Hanse-Wissenschaftskolleg Delmenhorst, Germany, sponsored the 'Marine Organic Biogeochemistry' workshop in April 2019, of which this working group report was a part. The Geochemical Society provided additional funding for the conference. AS was supported by DOE grant DE-SC0020369.
Subjects: 0106 biological sciences, Engineering, lcsh:QH1-199.5, 010504 meteorology & atmospheric sciences, Process (engineering), Ocean Engineering, lcsh:General. Including nature conservation, geographical distribution, Aquatic Science, Oceanography, 01 natural sciences, natural marine organic matter, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, 14. Life underwater, lcsh:Science, Reference standards, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Water Science and Technology, Global and Planetary Change, business.industry, 010604 marine biology & hydrobiology, analytical challenges, Biogeochemistry, chemometrics, Data science, marine organic biogeochemistry, Disparate system, HR-NMR, 13. Climate action, Ft icr ms, Paradigm shift, lcsh:Q, business, FT-ICR-MS
Abstract: International audience; Advances in sampling tools, analytical methods, and data handling capabilities have been fundamental to the growth of marine organic biogeochemistry over the past four decades. There has always been a strong feedback between analytical advances and scientific advances. However, whereas advances in analytical technology were often the driving force that made possible progress in elucidating the sources and fate oforganic matter in the ocean in the first decades of marine organic biogeochemistry, today process-based scientific questions should drive analytical developments. Several paradigm shifts and challenges for the future are related to the intersection between analytical progress and scientific evolution. Untargeted “molecular headhunting” for its own sake is now being subsumed into process-driven targeted investigations thatask new questions and thus require new analytical capabilities. However, there are still major gaps in characterizing the chemical composition and biochemical behavior of macromolecules, as well as in generating reference standards for relevant types of organic matter. Field-based measurements are now routinely complemented by controlled laboratory experiments and in situ rate measurements of key biogeochemicalprocesses. And finally, the multidisciplinary investigations that are becoming more common generate large and diverse datasets, requiring innovative computational tools to integrate often disparate data sets, including better global coverage and mapping. Here, we compile examples of developments in analytical methods that have enabled transformative scientific advances since 2004, and we project some challenges andopportunities in the near future. We believe that addressing these challenges and capitalizing on these opportunities will ensure continued progress in understanding the cycling of organic carbon in the ocean.
Published: 2020

28. Moroccan groundwater resources and evolution with global climate changes

Author: Ilham Bouimetarhan, Abdelfettah Sifeddine, Mohammed Hssaisoune, Ghani Chehbouni, Lhoussaine Bouchaou, Université Ibn Zohr [Agadir], Université Sultan Moulay Slimane (USMS ), Mohammed VI Polytechnic University [Marocco] (UM6P), Variabilité à long terme du climat de l'océan (VALCO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Universidade Federal Fluminense [Rio de Janeiro] (UFF), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Centre d'études spatiales de la biosphère (CESBIO), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université Mohammed VI Polytechnique [Ben Guerir] (UM6P), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: 010504 meteorology & atmospheric sciences, global changes, semi-arid, integrated management, Climate change, 010501 environmental sciences, Structural basin, 01 natural sciences, groundwater, Precipitation, [SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology, 0105 earth and related environmental sciences, lcsh:QE1-996.5, Groundwater recharge, 6. Clean water, lcsh:Geology, over-exploitation, Overexploitation, Morocco, Water security, 13. Climate action, General Earth and Planetary Sciences, Environmental science, Water resource management, Surface water, Groundwater
Abstract: In semi-arid areas, many ecosystems and activities depend essentially on water availability. In Morocco, the increase of water demands combined to climate change induced decrease of precipitation put a lot of pressure on groundwater. This paper reports the results of updating and evaluation of groundwater datasets with regards to climate scenarios and institutional choices. The continuous imbalance between groundwater extraction and recharge caused a dramatic decline in groundwater levels (20 to 65 m in the past 30 years). Additionally, Morocco suffers from the degradation in groundwater quality due to seawater intrusion, nitrate pollution and natural salinity changes. Climate data analysis and scenarios predict that temperatures will increase by 2 to 4 &deg, C and precipitation will decrease by 53% in all catchments over this century. Consequently, surface water availability will drastically decrease, which will lead to more extensive use of groundwater. Without appropriate measures, this situation will jeopardize water security in Morocco. In this paper, we zoom on the case the Souss-Massa basin, where management plans (artificial recharge, seawater desalination, and wastewater reuse) have been adopted to restore groundwater imbalance or, at least, mitigate the recorded deficits. These plans may save water for future generations and sustain crop production.
Published: 2020

29. Large-scale mass wasting on the Miocene continental margin of western India

Author: Sarah Dailey, Yuting Li, Rakesh Saxena, Tara N. Jonell, Anil Kumar, Manish Tiwari, Giancarlo Scardia, Rajeev Saraswat, Paul B. O'Sullivan, Annette Hahn, Gérôme Calvès, Lisa Tauxe, Sergio Andò, Claire M. Routledge, Boo-Keun Khim, Ravi Mishra, Dhananjai Pandey, Elizabeth M. Griffith, Girish Kumar Sharma, H. Liddy, Nikki E. Neubeck, T. Radhakrishna, James A Bendle, Zhaojie Yu, Jerzy S. Blusztajn, Masao Iwai, Kenta Suzuki, Arun Deo Singh, Denise K. Kulhanek, Mitchell W Lyle, G. P. Gurumurthy, A. Ganesh Kumar, Sophia Aharonovich, Stephan Steinke, Z. Xu, Giovanni Coletti, H. Lu, Peng Zhou, Peter D. Clift, Louisiana State Univ, Texas A&M Univ, Woods Hole Oceanog Inst, UCL, Univ Toulouse 3 Paul Sabatier, GeoSep Serv, Univ Queensland, Natl Ctr Polar & Ocean Res, Univ Milano Bicocca, Purdue Univ, Univ Birmingham, Macquarie Univ, Ohio State Univ, Birbal Sahni Inst Palaeosci, Univ Bremen, Kochi Univ, Pusan Natl Univ, Wadia Inst Himalayan Geol, Natl Inst Ocean Technol, Columbia Univ, Nanjing Univ, Oregon State Univ, Natl Ctr Earth Sci Studies, Natl Inst Oceanog, Oil & Nat Gas Commiss, Universidade Estadual Paulista (Unesp), Kumaun Univ, Banaras Hindu Univ, Xiamen Univ, Hokkaido Univ, Scripps Inst Oceanog, Chinese Acad Sci, Louisiana State University (LSU), Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), School of Materials Science and Technology, Institute of Technology, Banaras Hindu University, Banaras Hindu University [Varanasi] (BHU), Dipartimento di Scienze Geologiche e Geotecnologie, Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, BITS Pilani, K. K. Birla Campus, Goa (India), Nanjing University (NJU), DEPLAN/IGCE/UNESP, Instituto de Geociencias e Ciencias Exatas, Universidade de São Paulo (USP)-Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University (UNESP), Division of Medical Oncology, University of Colorado [Boulder], Indian Institute of Science, Key Laboratory of Marine Geology and Environment [China, Institute of Oceanology [China], Dailey, S, Clift, P, Kulhanek, D, Blusztajn, J, Routledge, C, Calvès, G, O’Sullivan, P, Jonell, T, Pandey, D, Ando', S, Coletti, G, Zhou, P, Yuting, L, Neubeck, N, Bendle, J, Aharonovich, S, Griffith, E, Gurumurthy, G, Hahn, A, Iwai, M, Khim, B, Kumar, A, Liddy, H, Huayu, L, Lyle, M, Mishra, R, Radhakrishna, T, Saraswat, R, Saxena, R, Scardia, G, Sharma, G, Singh, A, Steinke, S, Suzuki, K, Tauxe, L, Tiwari, M, Zhaokai, X, and Zhaojie, Y
Subjects: 010504 meteorology & atmospheric sciences, Geochemistry, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Mass-transport, Arabian Sea, IODP, heavy-minerals, Nataraja Slide, Expedition 355, Mass wasting, 010502 geochemistry & geophysics, 01 natural sciences, Continental margin, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Passive margin, 14. Life underwater, Siltstone, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, geography, geography.geographical_feature_category, Continental shelf, Geology, Calcarenite, Geophysics, [SDU]Sciences of the Universe [physics], [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Clastic rock, Siliciclastic
Abstract: Made available in DSpace on 2020-12-10T17:04:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Charles T. McCord Jr Chair in Petroleum Geology at Louisiana State University Ministry of Earth Sciences, Government of India National Centre for Polar and Ocean Research (NCPOR) National Research Foundation of Korea CSIR-National Institute of Oceanography, India A giant mass-transport complex was recently discovered in the eastern Arabian Sea, exceeding in volume all but one other known complex on passive margins worldwide. The complex, named the Nataraja Slide, was drilled by International Ocean Discovery Program (IODP) Expedition 355 in two locations where it is similar to 300 m (Site U1456) and similar to 200 m thick (Site U1457). The top of this mass-transport complex is defined by the presence of both reworked microfossil assemblages and deformation structures, such as folding and faulting. The deposit consists of two main phases of mass wasting, each consisting of smaller pulses, with generally fining-upward cycles, all emplaced just prior to 10.8 Ma based on biostratigraphy. The base of the deposit at each site is composed largely of matrix-supported carbonate breccia that is interpreted as the product of debris-flows. In the first phase, these breccias alternate with well-sorted calcar-enites deposited from a high-energy current, coherent limestone blocks that are derived directly from the Indian continental margin, and a few clastic mudstone beds. In the second phase, at the top of the deposit, muddy turbidites dominate and become increasingly more siliciclastic. At Site U1456, where both phases are seen, a 20-m section of hemipelagic mudstone is present, overlain by a similar to 40-m-thick section of calcarenite and slumped interbedded mud and siltstone. Bulk sediment geochemistry, heavy-mineral analysis, clay mineralogy, isotope geochemistry, and detrital zircon U-Pb ages constrain the provenance of the clastic, muddy material to being reworked, Indus-derived sediment, with input from western Indian rivers (e.g., Narmada and Tapti rivers), and some material from the Deccan Traps. The carbonate blocks found within the breccias are shallow-water limestones from the outer western Indian continental shelf, which was oversteepened from enhanced clastic sediment delivery during the mid-Miocene. The final emplacement of the material was likely related to seismicity as there are modern intraplate earthquakes close to the source of the slide. Although we hypothesize that this area is at low risk for future mass wasting events, it should be noted that other oversteepened continental margins around the world could be at risk for mass failure as large as the Nataraja Slide. Louisiana State Univ, Dept Geol & Geophys, E253 Howe Russell Kniffen Geosci Complex, Baton Rouge, LA 70803 USA Texas A&M Univ, Int Ocean Discovery Program, 1000 Discovery Dr, College Stn, TX 77845 USA Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA UCL, Dept Earth Sci, Gower St, London WC1E 6BT, England Univ Toulouse 3 Paul Sabatier, Geosci Environm Toulouse, 14 Ave Edouard Belin, F-31400 Toulouse, France GeoSep Serv, 1521 Pine Cone Rd, Moscow, ID 83843 USA Univ Queensland, Sch Earth & Environm Sci, St Lucia, Qld 4072, Australia Natl Ctr Polar & Ocean Res, Vasco Da Gama 403804, Goa, India Univ Milano Bicocca, Dept Earth & Environm Sci, Piazza Sci 4, I-20126 Milan, Italy Purdue Univ, Dept Earth Atmospher & Planetary Sci, 550 Stadium Mall Dr, W Lafayette, IN 47907 USA Univ Birmingham, Sch Geog Earth & Environm Sci, Birmingham B15 2TT, W Midlands, England Macquarie Univ, Fac Sci & Engn, Dept Earth & Planetary Sci, N Ryde, NSW 2109, Australia Ohio State Univ, Sch Earth Sci, 275 Mendenhall Lab,125 South Oval Mall, Columbus, OH 43210 USA Birbal Sahni Inst Palaeosci, 53 Univ Rd, Lucknow 226007, Uttar Pradesh, India Univ Bremen, MARUM, Leobener Str, D-28359 Bremen, Germany Kochi Univ, Dept Nat Environm Sci, 2-5-1 Akebono Cho, Kochi 7808520, Japan Pusan Natl Univ, Div Earth Environm Syst, Busan 60973, South Korea Wadia Inst Himalayan Geol, 33 GMS Rd, Dehra Dun 248001, Uttrakhand, India Natl Inst Ocean Technol, Marine Biotechnol Dept, Velacheiy Tambaram Main Rd, Chennai 600100, Tamil Nadu, India Columbia Univ, Ctr Climate Syst Res, 2880 Broadway, New York, NY 10025 USA Nanjing Univ, Sch Geog & Oceanog Sci, 163 Xianlin Ave, Nanjing 210023, Jiangsu, Peoples R China Oregon State Univ, Coll Earth Ocean & Atmospher Sci, 104 CEOAS Adm Bldg, Corvallis, OR 97331 USA Natl Ctr Earth Sci Studies, Geosci Div, Aakkulam Trivandrum 695031, India Natl Inst Oceanog, Geol Oceanog Div, Panaji 403004, Goa, India Oil & Nat Gas Commiss, 11 High,Bandra Sion Link Rd, Mumbai 400017, Maharashtra, India Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, 1515 Ave 24-A, BR-13506900 Rio Claro, SP, Brazil Kumaun Univ, Dept Geol, Naini Tal 263002, India Banaras Hindu Univ, Dept Geol, Varanasi 221005, Uttar Pradesh, India Xiamen Univ, Dept Geol Oceanog, Xiamen 361102, Fujian, Peoples R China Xiamen Univ, State Key Lab Marine Environm Sci, Xiamen 361102, Fujian, Peoples R China Hokkaido Univ, Grad Sch Environm Sci, Kita Ku, N10W5, Sapporo, Hokkaido 0600810, Japan Scripps Inst Oceanog, 9500 Gilman Dr, La Jolla, CA 92093 USA Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, 7 Nanhai Rd, Qingdao 266071, Shandong, Peoples R China Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, 1515 Ave 24-A, BR-13506900 Rio Claro, SP, Brazil National Centre for Polar and Ocean Research (NCPOR): 90/2018 National Research Foundation of Korea: 2016R1A2B4008256 National Research Foundation of Korea: 2019R1A2C1007701
Published: 2020

30. Climate-induced changes in the suitable habitat of cold-water corals and commercially important deep-sea fishes in the North Atlantic

Author: Tina N. Molodtsova, Pablo Durán Muñoz, Oisín Callery, Paul V. R. Snelgrove, Lea-Anne Henry, Marina Carreiro-Silva, Mathieu Woillez, J. Murray Roberts, Stefán Á. Ragnarsson, Vonda E. Wareham Hayes, Ellen Kenchington, Margaret A. Treble, Carlos Dominguez-Carrió, Francesco Mastrototaro, David Stirling, David W. Johnson, Chih-Lin Wei, Ryan Gasbarro, Kent Gilkinson, Kevin J. Hedges, Mariano Koen-Alonso, Pascal Laffargue, Anthony Grehan, Matthew Gianni, Cam Lirette, Cristina Gutiérrez-Zárate, Andrew J. Davies, Wojciech Walkusz, Telmo Morato, Covadonga Orejas, Sandrine Vaz, Les Watling, Gerald H. Taranto, Dick van Oevelen, Jesús Rivera, Patricia Puerta, José L. Rueda, Íris Sampaio, Javier Urra, Giovanni Chimienti, Steve W. Ross, Sophie Arnaud-Haond, André Freiwald, Jake Rice, Dierk Hebbeln, Claudia Wienberg, Lisa A. Levin, Mar Sacau, Berta Ramiro-Sánchez, Erik E. Cordes, Lindsay Beazley, Lenaick Menot, José-Manuel González-Irusta, Maria Grazia Pennino, F.J. Murillo, Ana García-Alegre, Johanne Vad, Andrew K. Sweetman, Hronn Egilsdottir, Marine and Environmental Sciences Centre [Portugal] (MARE), Instituto Universitário de Ciências Psicológicas, Sociais e da Vida = University Institute of Psychological, Social and Life Sciences (ISPA), Instituto do Mar - Universidade dos Açores (IMAR-UAc), Instituto Español de Oceanografía (IEO), Málaga., Institute of Marine Sciences / Institut de Ciències del Mar [Barcelona] (ICM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), National University of Ireland [Galway] (NUI Galway), MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Fisheries and Oceans Canada (DFO), Consorzio Nazionale Interuniversitario per le Scienze del Mare [Rome, Italie] (CoNISma), Università degli studi di Bari Aldo Moro = University of Bari Aldo Moro (UNIBA), Temple University [Philadelphia], Pennsylvania Commonwealth System of Higher Education (PCSHE), Institute of Freshwater Research, Department of Aquatic Resources, Swedish University of Agricultural Sciences (SLU)-Swedish University of Agricultural Sciences (SLU), Senckenberg am Meer, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, University of Edinburgh, University College of London [London] (UCL), Laboratoire Environnement Profond (LEP), Etudes des Ecosystèmes Profonds (EEP), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), P.P. Shirshov Institute of Oceanology (SIO), Russian Academy of Sciences [Moscow] (RAS), Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Memorial University of Newfoundland = Université Memorial de Terre-Neuve [St. John's, Canada] (MUN), Marine Scotland Science (MSS), University of Hawai‘i [Mānoa] (UHM), Instituto Universitário de Ciências Psicológicas, Sociais e da Vida (ISPA), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD), University of Bari Aldo Moro (UNIBA), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU), and Memorial University of Newfoundland [St. John's]
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, Coral, Biodiversity, cold-water corals, habitat, ocean acidification, 01 natural sciences, thermal tolerance, Lophelia, SponGES, Primary Research Article, Pesquerías, octocorals, General Environmental Science, deep‐sea, Global and Planetary Change, geography.geographical_feature_category, biology, Ecology, Octocorallia, Coral reef, Biological Sciences, ATLAS, fishes, climate change, Habitat, cod gadus-morhua, scleractinian corals, deep water, Medio Marino y Protección Ambiental, [SDE.MCG]Environmental Sciences/Global Changes, water, Climate change, 010603 evolutionary biology, Scleractinia, Centro Oceanográfico de Vigo, Environmental Chemistry, Pisces [Fish], 14. Life underwater, European Union, Deep-sea Sponge Grounds Ecosystems of the North Atlantic: an Integrated approach towards their preservation and sustainable exploitation, habitat suitability modelling, species distribution models, climate, 0105 earth and related environmental sciences, fish, geography, Horizon 2020, deep-sea, envelope models, lophelia-pertusa, cold‐water corals, Grant Agreement No 679849, 15. Life on land, biology.organism_classification, Primary Research Articles, Environmental niche modelling, Climate Action, A transatlantic assessment and deep-water ecosystem-based spatial management plan for Europe, vulnerable marine ecosystems, 13. Climate action, fisheries, scleractinians, Foundation species, Environmental science, calcification rates, protected areas, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Grant Agreement No 678760, Environmental Sciences
Abstract: The deep sea plays a critical role in global climate regulation through uptake and storage of heat and carbon dioxide. However, this regulating service causes warming, acidification and deoxygenation of deep waters, leading to decreased food availability at the seafloor. These changes and their projections are likely to affect productivity, biodiversity and distributions of deep-sea fauna, thereby compromising key ecosystem services. Understanding how climate change can lead to shifts in deep-sea species distributions is critically important in developing management measures. We used environmental niche modelling along with the best available species occurrence data and environmental parameters to model habitat suitability for key cold-water coral and commercially important deep-sea fish species under present-day (1951–2000) environmental conditions and to project changes under severe, high emissions future (2081–2100) climate projections (RCP8.5 scenario) for the North Atlantic Ocean. Our models projected a decrease of 28%–100% in suitable habitat for cold-water corals and a shift in suitable habitat for deep-sea fishes of 2.0°–9.9° towards higher latitudes. The largest reductions in suitable habitat were projected for the scleractinian coral Lophelia pertusa and the octocoral Paragorgia arborea, with declines of at least 79% and 99% respectively. We projected the expansion of suitable habitat by 2100 only for the fishes Helicolenus dactylopterus and Sebastes mentella (20%–30%), mostly through northern latitudinal range expansion. Our results projected limited climate refugia locations in the North Atlantic by 2100 for scleractinian corals (30%–42% of present-day suitable habitat), even smaller refugia locations for the octocorals Acanella arbuscula and Acanthogorgia armata (6%–14%), and almost no refugia for P. arborea. Our results emphasize the need to understand how anticipated climate change will affect the distribution of deep-sea species including commercially important fishes and foundation species, and highlight the importance of identifying and preserving climate refugia for a range of area-based planning and management tools., ATLAS, A Trans-AtLantic Assessment and deep-water ecosystem-based Spatial management plan for Europe, SI
Published: 2020

31. Integrating palaeoclimate time series with rich metadata for uncertainty modelling: strategy and documentation of the PalMod 130k marine palaeoclimate data synthesis

Author: Michael Langner, Olivier Cartapanis, Lukas Jonkers, Anne Strack, Stefan Mulitza, Michal Kucera, Nicholas P. McKay, Oeschger Centre for Climate Change Research (OCCR), University of Bern, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, School of Earth and Sustainability, Northern Arizona University [Flagstaff], and Bundesministerium fur Bildung und Forschung (PalMod grant) - Swiss National Science FoundationPP00P2-144811
Subjects: Data descriptor, 010504 meteorology & atmospheric sciences, Computer science, Western Iberian Margin, Climate change, South China Sea, Millennial-scale Changes, Intermediate Water, 010502 geochemistry & geophysics, Southeastern New-zealand, 01 natural sciences, Eastern Equatorial Pacific, law.invention, Llast Deglaciation, Set (abstract data type), 03 medical and health sciences, Documentation, law, Northern-hemisphere Climate, Sea-surface Temperature, Radiocarbon dating, 14. Life underwater, [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology, 550 Earth sciences & geology, lcsh:Environmental sciences, 030304 developmental biology, 0105 earth and related environmental sciences, lcsh:GE1-350, NetCDF, 0303 health sciences, Information retrieval, lcsh:QE1-996.5, computer.file_format, lcsh:Geology, Metadata, 13. Climate action, Atlantic Deep-water, [SDU]Sciences of the Universe [physics], General Earth and Planetary Sciences, Climate model, computer
Abstract: Palaeoclimate data hold the unique promise of providing a long-term perspective on climate change and as such can serve as an important benchmark for climate models. However, palaeoclimate data have generally been archived with insufficient standardisation and metadata to allow for transparent and consistent uncertainty assessment in an automated way. Thanks to improved computation capacity, transient palaeoclimate simulations are now possible, calling for data products containing multi-parameter time series rather than information on a single parameter for a single time slice. Efforts are underway to simulate a complete glacial–interglacial cycle using general circulation models (https://www.palmod.de/, last access: 6 May 2020), and to confront these simulations with palaeoclimate data, we have compiled a multi-parameter marine palaeoclimate data synthesis that contains time series spanning 0 to 130 000 years ago. We present the first version of the data product that focuses exclusively on time series for which a robust chronology based on benthic foraminifera δ18O and radiocarbon dating is available. The product contains 896 time series of eight palaeoclimate parameters from 143 individual sites, each associated with rich metadata, age–depth model ensembles, and information to refine and update the chronologies. This version contains 205 time series of benthic foraminifera δ18O; 169 of benthic foraminifera δ13C; 131 of seawater temperature; 174 and 119 of planktonic foraminifera δ18O and δ13C; and 44, 38 and 16 of carbonate, organic carbon and biogenic silica content, respectively. The data product is available in three formats (R, LiPD and netCDF) facilitating use across different software and operating systems and can be downloaded at https://doi.org/10.1594/PANGAEA.908831 (Jonkers et al., 2019). This data descriptor presents our data synthesis strategy and describes the contents and format of the data product in detail. It ends with a set of recommendations for data archiving.
Published: 2020

32. A lower to middle Eocene astrochronology for the Mentelle Basin (Australia) and its implications for the geologic time scale

Author: Carl Richter, Kenneth G. MacLeod, Sietske J. Batenburg, David De Vleeschouwer, Brian T. Huber, Heiko Pälike, Kirsty M. Edgar, Maximilian Vahlenkamp, Mathieu Martinez, Richard Hobbs, Kara Bogus, Emma Hanson, Yongxiang Li, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Géosciences Rennes (GR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), University of Birmingham [Birmingham], University of Missouri [Columbia] (Mizzou), University of Missouri System, Nanjing University (NJU), University of Louisiana, University of Exeter, Texas A&M University [College Station], Durham University, Smithsonian Institution, 617462, European Research Council, NE/R012350/1, Natural Environment Research Council, Centre National de la Recherche Scientifique, OCE – 1326927, National Science Foundation, Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)
Subjects: 010504 meteorology & atmospheric sciences, astrochronology, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Biostratigraphy, 010502 geochemistry & geophysics, Eocene, 01 natural sciences, Paleontology, Geologic time scale, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), 14. Life underwater, Magnetostratigraphy, 0105 earth and related environmental sciences, Astrochronology, IODP 369, Mentelle Basin, International Ocean Discovery Program, astronomical forcing, Geophysics, Stratigraphy, 13. Climate action, Space and Planetary Science, Sedimentary rock, Cenozoic, Geology
Abstract: International audience; The geologic time scale for the Cenozoic Era has been notably improved over the last decades by virtue of integrated stratigraphy, combining high-resolution astrochronologies, biostratigraphy and magnetostratigraphy with high-precision radioisotopic dates. However, the middle Eocene remains a weak link. The so-called “Eocene time scale gap” reflects the scarcity of suitable study sections with clear astronomically-forced variations in carbonate content, primarily because large parts of the oceans were starved of carbonate during the Eocene greenhouse. International Ocean Discovery Program (IODP) Expedition 369 cored a carbonate-rich sedimentary sequence of Eocene age in the Mentelle Basin (Site U1514, offshore southwest Australia). The sequence consists of nannofossil chalk and exhibits rhythmic clay content variability. Here, we show that IODP Site U1514 allows for the extraction of an astronomical signal and the construction of an Eocene astrochronology, using 3-cm resolution X-Ray fluorescence (XRF) core scans. The XRF-derived ratio between calcium and iron content (Ca/Fe) tracks the lithologic variability and serves as the basis for our U1514 astrochronology. We present a 16 million-year-long (40-56 Ma) nearly continuous history of Eocene sedimentation with variations paced by eccentricity and obliquity. We supplement the high-resolution XRF data with low-resolution bulk carbon and oxygen isotopes, recording the long-term cooling trend from the Paleocene-Eocene Thermal Maximum (PETM – ca. 56 Ma) into the middle Eocene (ca. 40 Ma). Our early Eocene astrochronology corroborates existing chronologies based on deep-sea sites and Italian land sections. For the middle Eocene, the sedimentological record at U1514 provides a single-site geochemical backbone and thus offers a further step towards a fully integrated Cenozoic geologic time scale at orbital resolution.
Published: 2020

33. From platform top to adjacent deep sea: New source-to-sink insights into carbonate sediment production and transfer in the SW Indian Ocean (Glorieuses archipelago)

Author: Elda Miramontes, Samuel Toucanne, Simon Courgeon, Gwenael Jouet, Evan N. Edinger, John W. Counts, Pascal Roy, Gilbert Camoin, Stephan J. Jorry, Natalia Vázquez Riveiros, Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Unité de recherche Géosciences Marines (Ifremer) (GM), Mem Univ Newfoundland, Dept Biol, St John, NF, Canada, Partenaires INRAE, University College Dublin [Dublin] (UCD), Universität Bremen, Domaines Océaniques (LDO), Centre National de la Recherche Scientifique (CNRS)-Institut d'écologie et environnement-Observatoire des Sciences de l'Univers-Université de Brest (UBO)-Institut national des sciences de l'Univers (INSU - CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), TOTAL [FR00006152], IFREMER, CNRSCentre National de la Recherche Scientifique (CNRS), France's 'Iles Eparses' program, CEREGE, 'Laboratoire d'Excellence' LabexMER [ANR-10-LABX-19], French Government, Regional Council of Brittany (SAD program)Region Bretagne, Memorial University of Newfoundland sabbatical research grant, NSERCNatural Sciences and Engineering Research Council of Canada, IFPEN, Universite de Rennes, Universite de Brest, UPMC, ANR-10-LABX-0019,LabexMER,LabexMER Marine Excellence Research: a changing ocean(2010), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS), and Laboratoire Environnements Sédimentaires - Géosciences Marines (GM/LES)
Subjects: 010504 meteorology & atmospheric sciences, Carbonate platform, Carbonate budget, Structural basin, engineering.material, 010502 geochemistry & geophysics, Oceanography, 01 natural sciences, Deep sea, Paleontology, chemistry.chemical_compound, Geochemistry and Petrology, 14. Life underwater, Indian Ocean, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Continental shelf, Aragonite, Geology, Coral reef, Calciturbidite, Sedimentary basin, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, chemistry, 13. Climate action, [SDE]Environmental Sciences, engineering, Carbonate, Siliciclastic
Abstract: International audience; Over the past ten years, a huge amount of source-to-sink studies have aimed to unravel the tectonic, climatic and other processes that shape the landscape from mountains to the deep ocean. Interestingly, these studies have been mainly dedicated to siliciclastic or mixed systems, for which the connection between drainage basins, continental shelves, slope and basin environments are often well constrained. Here we present a study focusing on a source-to-sink study dedicated to a pure carbonate system, located in the SW Indian Ocean (Glorieuses archipelago). Extensive field sampling and geophysical acquisition across the carbonate platform have allowed us to estimate the composition, the lateral variability, and volumes of neritic sands deposited on the platform top. Additional seismic and bathymetric surveys across the platform interior illustrate the presence of plurimetric sandy bodies deposited along the leeward platform edge, corresponding to the export of carbonate sediments from the platform top toward the platform edge, under the influence of dominant currents and winddriven processes. High-resolution seismic, bathymetric data and sediment cores acquired along the leeward slope and basin adjacent to the carbonate platform highlight the presence of channel-levee complexes and turbiditic lobes, which have accumulated on the seafloor on top of a 250 m-thick sedimentary basin at 2000-3400 m water depth. Our study points out that carbonate sands and aragonitic mud produced on the platform top during the Holocene have been shed to the adjacent basin. We also demonstrate that this routing system was active at least throughout the last three glacial/interglacial cycles. This study has important consequences for our understanding of carbonate sedimentation processes occurring in the vicinity of isolated carbonate platforms: 1 - it highlights the role of oceanographic conditions in the distribution of sediment on a platform top and its export along the platform edge and the adjacent basin; 2 - it contributes to quantify the productivity of a carbonate platform as well as its sediment storage capacity; 3 - a first estimate of a carbonate source-to-sink system is proposed, demonstrating that 0,57 km(3) of sediments have been produced during the Holocene, 0,3 km(3) being presently stored on the platform, and the remaining having been exported to the deep basin.
Published: 2020

34. New guidelines for the application of Stokes' models to the sinking velocity of marine aggregates

Author: Christina L. De La Rocha, Morgane Gallinari, Anja Engel, Frédéric A. C. Le Moigne, Brivaëla Moriceau, E. C. Laurenceau-Cornec, Morten Hvitfeldt Iversen, Jordan Toullec, Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Alfred Wegener Institute for Polar and Marine Research (AWI), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Funding Information Australian Research Council. Grant Number: FL160100131 CalMaro FP7 Marie Curie Initial Training Network. Grant Number: 215157 EURO‐BASIN. Grant Number: 264933, European Project: 264933,EC:FP7:ENV,FP7-ENV-2010,EURO-BASIN(2010), European Project: 215157,EC:FP7:PEOPLE,FP7-PEOPLE-2007-1-1-ITN,CALMARO(2008), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Drag coefficient, 010504 meteorology & atmospheric sciences, SOLID PARTICLES, Aquatic Science, RESPIRATION RATES, Oceanography, 01 natural sciences, Fractal dimension, Sphericity, Physics::Geophysics, CARBON EXPORT, Physics::Fluid Dynamics, symbols.namesake, SETTLING VELOCITY, Settling, 14. Life underwater, FECAL PELLETS, Porosity, IMAGE-ANALYSIS, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010604 marine biology & hydrobiology, Aggregate (data warehouse), Reynolds number, Mechanics, OCEAN BIOGEOCHEMICAL MODEL, 13. Climate action, symbols, Particle, Environmental science, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, PARTICULATE ORGANIC-MATTER, DUST-DEPOSITION, FRACTAL DIMENSIONS
Abstract: International audience; Numerical simulations of ocean biogeochemical cycles need to adequately represent particle sinking velocities (SV). For decades, Stokes' Law estimating particle SV from density and size has been widely used. But while Stokes' Law holds for small, smooth, and rigid spheres settling at low Reynolds number, it fails when applied to marine aggregates complex in shape, structure, and composition. Minerals and zooplankton can alter phytoplankton aggregates in ways that change their SV, potentially improving the applicability of Stokes' models. Using rolling cylinders, we experimentally produced diatom aggregates in the presence and absence of minerals and/or microzooplankton. Minerals and to a lesser extent microzooplankton decreased aggregate size and roughness and increased their sphericity and compactness. Stokes' Law parameterized with a fractal porosity modeled adequately size-SV relationships for mineral-loaded aggregates. Phytoplankton-only aggregates and those exposed to microzooplankton followed the general Navier-Stokes drag equation suggesting an indiscernible effect of microzooplankton and a drag coefficient too complex to be calculated with a Stokes' assumption. We compared our results with a larger data set of ballasted and nonballasted marine aggregates. This confirmed that the size-SV relationships for ballasted aggregates can be simulated by Stokes' models with an adequate fractal porosity parameterization. Given the importance of mineral ballasting in the ocean, our findings could ease biogeochemical model parameterization for a significant pool of particles in the ocean and especially in the mesopelagic zone where the particulate organic matter : mineral ratio decreases. Our results also reinforce the importance of accounting for porosity as a decisive predictor of marine aggregate SV.
Published: 2019

35. Ventilation of the Deep Ocean Carbon Reservoir During the Last Deglaciation: Results From the Southeast Pacific

Author: Consuelo Martínez Fontaine, Lowell D. Stott, Ricardo De Pol-Holz, D Reyes-Macaya, Elisabeth Michel, John Southon, Giuseppe Siani, Tim DeVries, Dierk Hebbeln, Gema Martínez-Méndez, Mahyar Mohtadi, Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Univ Chile, Dept Geol, Santiago, Univ Magallanes, Ctr Invest GAIA Antarct CIGA & Network Extreme En, Punta Arenas, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Paléocéanographie (PALEOCEAN), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Univ Bremen, Ctr Marine Environm Sci, MARUM, Bremen, Department of Atmospheric and Oceanic Sciences [Los Angeles] (AOS), University of California [Los Angeles] (UCLA), University of California-University of California, Univ Southern Calif, Dept Earth Sci, Los Angeles, CA 90007, University of California [Irvine] (UCI), University of California, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), University of California (UC)-University of California (UC), University of California [Irvine] (UC Irvine), and University of California (UC)
Subjects: Atmospheric Science, Antarctic Intermediate Water, 010504 meteorology & atmospheric sciences, biology, Ocean current, Paleontology, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Last Glacial Maximum, 010502 geochemistry & geophysics, Oceanography, biology.organism_classification, 01 natural sciences, Deep sea, Foraminifera, Continental margin, 13. Climate action, [SDU]Sciences of the Universe [physics], Deglaciation, 14. Life underwater, Glacial period, Geology, 0105 earth and related environmental sciences
Abstract: International audience; Coeval changes in atmospheric CO2 and C-14 contents during the last deglaciation are often attributed to ocean circulation changes that released carbon stored in the deep ocean during the Last Glacial Maximum (LGM). Work is being done to generate records that allow for the identification of the exact mechanisms leading to the accumulation and release of carbon from the oceanic reservoir, but these mechanisms are still the subject of debate. Here we present foraminifera C-14 data from five cores in a transect across the Chilean continental margin between similar to 540 and similar to 3,100 m depth spanning the last 20,000 years. Our data reveal that during the LGM, waters at similar to 2,000 m were 50% to 80% more depleted in Delta C-14 than waters at similar to 1,500 m when compared to modern values, consistent with the hypothesis of a glacial deep ocean carbon reservoir that was isolated from the atmosphere. During the deglaciation, our intermediate water records reveal homogenization in the Delta C-14 values between similar to 800 and similar to 1,500 m from similar to 16.5-14.5 ka cal BP to similar to 14-12 ka cal BP, which we interpret as deeper penetration of Antarctic Intermediate Water. While many questions still remain, this process could aid the ventilation of the deep ocean at the beginning of the deglaciation, contributing to the observed similar to 40 ppm rise in atmospheric pCO(2).
Published: 2019

36. Expanding Tara Oceans Protocols for Underway, Ecosystemic Sampling of the Ocean-Atmosphere Interface During Tara Pacific Expedition (2016–2018)

Author: Gorsky, Gabriel, Bourdin, Guillaume, Lombard, Fabien, Pedrotti, Maria Luiza, Audrain, Samuel, Bin, Nicolas, Boss, Emmanuel, Bowler, Chris, Cassar, Nicolas, Caudan, Loic, Chabot, Genevieve, Cohen, Natalie R., Cron, Daniel, De Vargas, Colomban, Dolan, John R., Douville, Eric, Elineau, Amanda, Flores, J. Michel, Ghiglione, Jean Francois, Haentjens, Nils, Hertau, Martin, John, Seth G., Kelly, Rachel L., Koren, Ilan, Lin, Yajuan, Marie, Dominique, Moulin, Clementine, Moucherie, Yohann, Pesant, Stephane, Picheral, Marc, Poulain, Julie, Pujo-pay, Mireille, Reverdin, Gilles, Romac, Sarah, Sullivan, Mathew B., Trainic, Miri, Tressol, Marc, Trouble, Romain, Vardi, Assaf, Voolstra, Christian R., Wincker, Patrick, Agostini, Sylvain, Banaigs, Bernard, Boissin, Emilie, Forcioli, Didier, Furla, Paola, Galand, Pierre E., Gilson, Eric, Reynaud, Stephanie, Sunagawa, Shinichi, Thomas, Olivier P., Thurber, Rebecca Lisette Vega, Zoccola, Didier, Planes, Serge, Allemand, Denis, Karsenti, Eric, Planes, S., Banaig, B., Boissin, E., Iwankow, G., Allemand, D., Zoccola, D., Reynaud, S., Beraud, E., Djerbi, N., Forcioli, D., Furla, P., Gilson, E., Mcmind, R., Ottaviani, A., Rottinger, E., Rouan, A., Zamoum, T., Flume, B. C. C., Pogoreutz, C., Voolstra, C. R., Rothig, T., Ziegler, M., Paoli, L., Ruscheweyh, H-j, Salazar, G., Sunagawa, S., Flores, J. M., Koren, I, Trainic, M., Lang-yona, N., Vardi, A., Conan, P., Ghiglione, J-f, Pujo-pay, M., Galand, P. E., Hochart, C., Audrain, S., Bourgois, E., Hertau, M., Lancelot, J., Monmarche, D., Moulin, C., Moucherie, Y., Trouble, R., Boss, E., Bourdin, G., Haentjens, N., Karp-boss, L., Agostini, S., Mitsuhashi, G., Kitano, Y., Da Silva, O., Dolan, J. R., Gorsky, G., Lemee, R., Lombard, F., Pedrotti, M-l, Cronin, D., Sullivan, M., Armstrong, E., Aury, J-m, Barbe, V, Belser, C., Carradec, Q., Labadie, K., Le-hoang, J., Noel, B., Poulain, J., Wincker, P., Klinges, G., Vega-thunder, R., Bonnival, E., De Vargas, C., Henry, N., Marie, D., Romac, S., Pesant, S., Miguel-gorda, M., Thomas, O. P., Bowler, C., Friedrich, R., Cassar, N., Lin, Y., John, S. G., Kelly, R. L., Cohen, N. R., Reverdin, G., Filee, J., Pedrotti, Maria Luiza, Organisation et montée en puissance d'une Infrastructure Nationale de Génomique - - France-Génomique2010 - ANR-10-INBS-0009 - INBS - VALID, Laboratoires d'excellence - LabexMER Marine Excellence Research: a changing ocean - - LabexMER2010 - ANR-10-LABX-0019 - LABX - OLD, Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of Maine, Tara Expéditions, Institut de biologie de l'Ecole Normale Supérieure (IBENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Nicholas School of the Environment, Duke University [Durham], Mercator Océan, Société Civile CNRS Ifremer IRD Météo-France SHOM, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Woods Hole Oceanographic Institution (WHOI), Evolution des Protistes et Ecosystèmes Pélagiques (EPEP), Adaptation et diversité en milieu marin (AD2M), Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Géochrononologie Traceurs Archéométrie (GEOTRAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Earth and Planetary Science [Rehovot], Weizmann Institute of Science [Rehovot, Israël], Laboratoire d'Océanographie Microbienne (LOMIC), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Southern California (USC), Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Data Publisher for Earth and Environmental Science (PANGAEA), University of Bremen, Genoscope - Centre national de séquençage [Evry] (GENOSCOPE), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Processus et interactions de fine échelle océanique (PROTEO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Department of Civil, Environmental and Geodetic Engineering [Columbus], Ohio State University [Columbus] (OSU), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Universität Konstanz, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Shimoda Marine Research Center, Université de Tsukuba = University of Tsukuba, Laboratoire d'Excellence CORAIL (LabEX CORAIL), Institut de Recherche pour le Développement (IRD)-Université des Antilles et de la Guyane (UAG)-École des hautes études en sciences sociales (EHESS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de La Réunion (UR)-Université de la Polynésie Française (UPF)-Université de la Nouvelle-Calédonie (UNC)-Institut d'écologie et environnement-Université des Antilles (UA), Centre de recherches insulaires et observatoire de l'environnement (CRIOBE), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Symbiose Marine (SM), Evolution Paris Seine, Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche sur le Cancer et le Vieillissement (IRCAN), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), Dpt génétique médicale [CHU Nice], Centre Hospitalier Universitaire de Nice (CHU Nice), Laboratoire d'Ecogéochimie des environnements benthiques (LECOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Centre Scientifique de Monaco (CSM), Department of Biology [ETH Zürich] (D-BIOL), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), National University of Ireland [Galway] (NUI Galway), Oregon State University (OSU), European Molecular Biology Laboratory [Heidelberg] (EMBL), TARA, ANR-10-INBS-0009,France-Génomique,Organisation et montée en puissance d'une Infrastructure Nationale de Génomique(2010), ANR-10-LABX-0019,LabexMER,LabexMER Marine Excellence Research: a changing ocean(2010), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Banyuls (OOB), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université des Antilles (UA)-Institut d'écologie et environnement-Université de la Nouvelle-Calédonie (UNC)-Université de la Polynésie Française (UPF)-Université de La Réunion (UR)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École des hautes études en sciences sociales (EHESS)-Université des Antilles et de la Guyane (UAG)-Institut de Recherche pour le Développement (IRD), Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (... - 2019) (UNS), Université Nice Sophia Antipolis (... - 2019) (UNS), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Université des Antilles et de la Guyane (UAG)-École des hautes études en sciences sociales (EHESS)-École Pratique des Hautes Études (EPHE), Université de Perpignan Via Domitia (UPVD)-École Pratique des Hautes Études (EPHE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, lcsh:QH1-199.5, [SDE.MCG]Environmental Sciences/Global Changes, trace metals, Ocean Engineering, neuston, Aquatic Science, lcsh:General. Including nature conservation, geographical distribution, Oceanography, 01 natural sciences, Pacific ocean, taxonomy, neuston/plankton genomics/taxonomy/imaging, ddc:570, Ecosystem, 14. Life underwater, lcsh:Science, Reef, 0105 earth and related environmental sciences, Water Science and Technology, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Global and Planetary Change, geography, geography.geographical_feature_category, aerosols, NCP, IOP, microplastic, plankton genomics, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere, ACL, 010604 marine biology & hydrobiology, Community structure, imaging, Pelagic zone, Plankton, Inlet, neuston/plankton genomics/taxonomy/imaging, aerosols, NCP, IOP, trace metals, microplastic, [SDE.BE] Environmental Sciences/Biodiversity and Ecology, [SDE.MCG] Environmental Sciences/Global Changes, 13. Climate action, lcsh:Q, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Neuston
Abstract: Interactions between the ocean and the atmosphere occur at the air-sea interface through the transfer of momentum, heat, gases and particulate matter, and through the impact of the upper-ocean biology on the composition and radiative properties of this boundary layer. The Tara Pacific expedition, launched in May 2016 aboard the schooner Tara, was a 29-month exploration with the dual goals to study the ecology of reef ecosystems along ecological gradients in the Pacific Ocean and to assess inter-island and open ocean surface plankton and neuston community structures. In addition, key atmospheric properties were measured to study links between the two boundary layer properties. A major challenge for the open ocean sampling was the lack of ship-time available for work at “stations”. The time constraint led us to develop new underway sampling approaches to optimize physical, chemical, optical, and genomic methods to capture the entire community structure of the surface layers, from viruses to metazoans in their oceanographic and atmospheric physicochemical context. An international scientific consortium was put together to analyze the samples, generate data, and develop datasets in coherence with the existing Tara Oceans database. Beyond adapting the extensive Tara Oceans sampling protocols for high-resolution underway sampling, the key novelties compared to Tara Oceans’ global assessment of plankton include the measurement of (i) surface plankton and neuston biogeography and functional diversity; (ii) bioactive trace metals distribution at the ocean surface and metal-dependent ecosystem structures; (iii) marine aerosols, including biological entities; (iv) geography, nature and colonization of microplastic; and (v) high-resolution underway assessment of net community production via equilibrator inlet mass spectrometry. We are committed to share the data collected during this expedition, making it an important resource important resource to address a variety of scientific questions. ISSN:2296-7745
Published: 2019

37. Seafloor sealing, doming, and collapse associated with gas seeps and authigenic carbonate structures at Venere mud volcano, Central Mediterranean

Author: Marta E Torres, Thomas Pape, Paul Wintersteller, Christian dos Santos Ferreira, Gerhard Bohrmann, Daniel Praeg, Yann Marcon, Miriam Römer, Markus Loher, Heiko Sahling, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Istituto Nazionale di Geofisica e di Oceanografia Sperimentale (OGS), Pontifícia Universidade Católica do Rio Grande do Sul [Porto Alegre] (PUCRS), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), College of Earth, Ocean and Atmospheric Sciences [Corvallis] (CEOAS), Oregon State University (OSU), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), and Pontifical Catholic University of Rio Grande do Sul (PUC-RS)
Subjects: Chemosynthesis, 010504 meteorology & atmospheric sciences, Clathrate hydrate, Geochemistry, Authigenic, Aquatic Science, 010502 geochemistry & geophysics, Oceanography, [SDE.ES]Environmental Sciences/Environmental and Society, 01 natural sciences, Seafloor spreading, Cold seep, chemistry.chemical_compound, chemistry, 13. Climate action, [SDE]Environmental Sciences, Anaerobic oxidation of methane, Carbonate, 14. Life underwater, ComputingMilieux_MISCELLANEOUS, Geology, 0105 earth and related environmental sciences, Mud volcano
Abstract: International audience; Methane release from the seafloor is commonly associated with chemosynthesis-based cold seep ecosystems that facilitate the precipitation of authigenic carbonates. It has been proposed that carbonate growth results in self-sealing, but little is known regarding the evolution of cold seep structures in relation to fluid migration pathways. This study investigates structures resulting from gas seepage along ring faults peripheral to Venere mud volcano (1600 m water depth), based on multibeam bathymetry and seafloor backscatter data collected by an autonomous underwater vehicle, together with photomosaics, video observations, and samples obtained by a remotely operated vehicle. Sites of focused fluid flow are identified by gas bubble streams rising from the seafloor while anaerobic oxidation of methane (AOM) over wider areas is indicated by the occurrence of chemosynthesis-based organisms (microbial mats, vesicomyid clams, vestimentiferan tube worms). At some sites, flakes of gas hydrate were observed in the water column during sampling. A range of carbonate structures exists at these sites: 1) flat and extensive pavements; 2) mounds with disseminated nodules or centimeter-thick crusts; 3) fractured mounds with exposed, decimeter-thick crusts; and 4) seafloor depressions lined by decimeter-thick crusts. The mineralogy and stable carbon isotopic compositions of the carbonates are consistent with anaerobic oxidation of methane from thermogenic sources, and possible near-seabed influence of gas hydrate formation and dissolution. The seafloor expressions of seepage are inferred to be controlled by the interaction of fluid flow due to carbonate precipitation and gas hydrate formation. A conceptual model for mound development is proposed in the context of the known timescales of seep-colonization and rates of carbonate precipitation: (A) the onset of hydrocarbon-rich fluid seepage through hemipelagic sediments leads to (B) the establishment of microbial mats on flat seafloor over decadal timescales and is followed by (C) the growth of pavements cemented by carbonates that seal the seafloor; over longer timescales (centuries to millennia), carbonate growth and subsurface gas hydrate formation/dissolution lead to (D) upward doming and fracturing of carbonate mounds, re-sealing and stacking of carbonates and in some cases to (E) their collapse to form seafloor depressions. Gas migration through fractures in the carbonates allows re-sealing and fuels AOM to provide habitats for chemosynthesis-based fauna. This evolutionary scenario is argued to be broadly applicable to the development of ruptured mounds and collapse features described at other seepage sites in the Mediterranean Sea and elsewhere.
Published: 2018

38. Synchronization of the astronomical time scales in the Early Toarcian: A link between anoxia, carbon-cycle perturbation, mass extinction and volcanism

Author: Mathieu Martinez, Gregory D. Price, Fatima-Zahra Ait-Itto, Abdellah Ait Addi, Université Cadi Ayyad [Marrakech] (UCA), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Géosciences Rennes (GR), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), School of Geography, Earth and Environmental Sciences [Plymouth] (SoGEES), Plymouth University, 617462, H2020 European Research Council, IAS, Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), and Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, astrochronology, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Perturbation (astronomy), Toarcian, Volcanism, 010502 geochemistry & geophysics, 01 natural sciences, Paleontology, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Geochemistry and Petrology, carbon cycle, Earth and Planetary Sciences (miscellaneous), 14. Life underwater, Mesozoic, 0105 earth and related environmental sciences, oceanic anoxic events, Extinction event, Astrochronology, geography, geography.geographical_feature_category, Igneous rock, Geophysics, Volcano, 13. Climate action, Space and Planetary Science, Radiometric dating, Middle Atlas, Geology
Abstract: International audience; The Late Pliensbachian–Early Toarcian is a pivotal time in the Mesozoic era, marked by pronounced carbon-isotope excursions, biotic crises and major climatic and oceanographic changes. Here we present new high-resolution carbon-isotope and magnetic-susceptibility measurements from an expanded hemipelagic Late Pliensbachian–Early Toarcian section from the Middle Atlas Basin (Morocco). Our new astronomical calibration allows the construction of an orbital time scale based on the 100-kyr eccentricity cycle. The Early Toarcian Polymorphum Zone contains 10 to 10.5 repetitions of the 100-kyr eccentricity both in the carbon-isotope and the magnetic-susceptibility data, leading to an average duration of 1.00±0.081.00±0.08 myr. We also show that the Late Pliensbachian–Early Toarcian global carbon-cycle perturbation has an average duration of 0.24±0.020.24±0.02 myr. These durations are comparable to previous astrochronological time scales provided for this time interval in the most complete sections of the Tethyan area, and longer than what has been provided in condensed sections. Anchoring this framework on published radiometric ages and astrochronological time scales, we estimate that the carbon-cycle perturbation of the Late Pliensbachian–Early Toarcian corresponds with the early phase of the Karoo and Chonke Aike large igneous provinces. Likewise, our new age constraints confirm that the Toarcian oceanic anoxic event is synchronous to the main phase of the Ferrar volcanic activity. Thus, these successive and short phases of the volcanic activity may have been at the origin of the successive phases of the mass extinctions observed in marine biotas in the Pliensbachian and Toarcian times.
Published: 2018

39. High-resolution marine data and transient simulations support orbital forcing of ENSO amplitude since the mid-Holocene

Author: Johann H. Jungclaus, Rachid Cheddadi, Xiaoxu Shi, Mary Elliot, Matthieu Carré, Olivier Marti, Bruno Turcq, Diana Ochoa, Pedro E. Romero, Isma Abdelkader di Carlo, Thierry Corrège, Roberta D'Agostino, Sandy P. Harrison, Andrew Schurer, Rodolfo Salas Gismondi, Pascale Braconnot, Alexander Pérez, Jorge Cardich, Gerrit Lohmann, Variabilité à long terme du climat de l'océan (VALCO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Universidad Peruana Cayetano Heredia (UPCH), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, School of Geosciences [Edinburgh], University of Edinburgh, Alfred Wegener Institute for Polar and Marine Research (AWI), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), University of Reading (UOR), ANR-15-JCLI-0003,PACMEDY,PAlaeo-Constraints on Monsoon Evolution and Dynamics(2015), ANR-17-EURE-0006,IPSL-CGS,IPSL Climate graduate school(2017), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226, and Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)
Subjects: El niño southern oscillation, Archeology, 010504 meteorology & atmospheric sciences, Orbital forcing, Orbits, Forcing (mathematics), Oceanography, 010502 geochemistry & geophysics, 01 natural sciences, Insolation, Holocene, El Nino southern oscillation, Climatology, Global and Planetary Change, Surface waters, Geology, Anthozoa, Earth system model, Corals, West pacific, Uncertainty analysis, Atmospheric pressure, Eastern pacific, Bivalves, Transient simulation, Tropical pacific, Earth system models, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Climate models, Interannual variability, Paleoclimatology, medicine, South Pacific convergence zone, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Incident solar radiation, Holocenes, Tropics, Molluscs, Seasonality, medicine.disease, Bivalvia, Sea surface temperature, [SDU]Sciences of the Universe [physics], 13. Climate action, Environmental science, Climate model, Coral
Abstract: International audience; Lack of constraint on spatial and long-term temporal variability of the El Niño southern Oscillation (ENSO) and its sensitivity to external forcing limit our ability to evaluate climate models and ENSO future projections. Current knowledge of Holocene ENSO variability derived from paleoclimate reconstructions does not separate the role of insolation forcing from internal climate variability. Using an updated synthesis of coral and bivalve monthly resolved records, we build composite records of seasonality and interannual variability in four regions of the tropical Pacific: Eastern Pacific (EP), Central Pacific (CP), Western Pacific (WP) and South West Pacific (SWP). An analysis of the uncertainties due to the sampling of chaotic multidecadal to centennial variability by short records allows for an objective comparison with transient simulations (mid-Holocene to present) performed using four different Earth System models. Sea surface temperature and pseudo-δ18O are used in model-data comparisons to assess the potential influence of hydroclimate change on records. We confirm the significance of the Holocene ENSO minimum (HEM) 3-6ka compared to low frequency unforced modulation of ENSO, with a reduction of ENSO variance of ∼50 % in EP and ∼80 % in CP. The approach suggests that the increasing trend of ENSO since 6ka can be attributed to insolation, while models underestimate ENSO sensitivity to orbital forcing by a factor of 4.7 compared to data, even when accounting for the large multidecadal variability. Precession-induced change in seasonal temperature range is positively linked to ENSO variance in EP and to a lesser extent in other regions, in both models and observations. Our regional approach yields insights into the past spatial expression of ENSO across the tropical Pacific. In the SWP, today under the influence of the South Pacific Convergence Zone (SPCZ), interannual variability was increased by ∼200 % during the HEM, indicating that SPCZ variability is independent from ENSO on millennial time scales.
Published: 2021

40. The erosive power of the Malvinas Current: Influence of bottom currents on morpho-sedimentary features along the northern Argentine margin (SW Atlantic Ocean)

Author: Camila Artana, F. Javier Hernández-Molina, Sabine Kasten, Volkhard Spieß, Alberto R. Piola, Michele Baqués, Elda Miramontes, Meret Felgendreher, Wenyan Zhang, Henriette Wilckens, Tilmann Schwenk, Christine Provost, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Mercator Océan, Société Civile CNRS Ifremer IRD Météo-France SHOM, Helmholtz-Zentrum Geesthacht (GKSS), Instituto Franco-Argentino sobre Estudios de Clima y sus Impactos [Buenos Aires] (IFAECI), Centro de Investigaciones del Mar y la Atmósfera (CIMA), Facultad de Ciencias Exactas y Naturales [Buenos Aires] (FCEyN), Universidad de Buenos Aires [Buenos Aires] (UBA)-Universidad de Buenos Aires [Buenos Aires] (UBA)-Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET)-Facultad de Ciencias Exactas y Naturales [Buenos Aires] (FCEyN), Universidad de Buenos Aires [Buenos Aires] (UBA)-Universidad de Buenos Aires [Buenos Aires] (UBA)-Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET)-Centre National de la Recherche Scientifique (CNRS), Departamento de Oceanografia, Servicio de Hidrografía Naval, Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Department of Earth Sciences, University of London, Queen Mary University of London (QMUL), Institute of Geosciences [Kiel], Christian-Albrechts-Universität zu Kiel (CAU), Alfred Wegener Institute for Polar and Marine Research (AWI), Servicio de Hidrografia Naval, Servicio de Hydrografia Naval, Instituto Franco-Argentino para el Estudio del Clima y sus Impactos (UMI IFAECI/CNRS-CONICET-UBA-IRD), Dpto. de Ciencias de la Atmosfera y losOceanos, FCEN, Universidad de Buenos Aire, Austral, Boréal et Carbone (ABC), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Department of Earth Sciences, Royal Holloway, University of London, Egham, University of Bremen, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET)-Facultad de Ciencias Exactas y Naturales [Buenos Aires] (FCEyN), Universidad de Buenos Aires [Buenos Aires] (UBA)-Universidad de Buenos Aires [Buenos Aires] (UBA)-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Ocean current, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Geology, Contourite, 010502 geochemistry & geophysics, Oceanography, 01 natural sciences, Seafloor spreading, Sedimentary structures, Sedimentary depositional environment, Terrace (geology), Continental margin, 13. Climate action, Geochemistry and Petrology, Sedimentary rock, 14. Life underwater, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Geomorphology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Sediment deposits formed mainly under the influence of bottom currents (contourites) are widely used as high-resolution archives for reconstructing past ocean conditions. However, the driving processes of Contourite Depositional Systems (CDS) are not entirely understood. The aim of this study is to establish a clearer link between contourite features and the oceanographic processes that form them. The morphosedimentary characteristics of a large CDS were analysed together with the current dynamics along the northern Argentine continental margin. This study combines multibeam bathymetry, seismo-acoustic data, sediment samples, vessel-mounted Acoustic Doppler Current Profiler (VM-ADCP) data and numerical modelling of ocean currents. The contouritic features include large contourite terraces (La Plata Terrace, Ewing Terrace) and an abraded surface connecting the terraces, as well as smaller erosional and depositional features like moats, erosion surfaces on the Ewing Terrace, sediment waves and contourite drifts. Measured and modelled near-bottom currents are vigorous (up to 63 cm/s at 150–200 m above the seafloor) where abraded surfaces and moats are present, and relatively weak (below 30 cm/s) on the La Plata Terrace and the Ewing Terrace. Generally, bottom currents follow the upper and middle slope morphology. Decreasing velocity of water masses flowing northward leads to less erosion and finer sediment deposits. ADCP data and the hydrodynamic model show the formation of eddies near the seafloor which probably lead to the small erosion surfaces on the Ewing Terrace, even though it is mainly a depositional environment. Overall, this study contributes to a better understanding of the formation of CDS and can help future reconstructions of past ocean conditions based on sedimentary structures.
Published: 2021

41. Production rates of bacterial tetraether lipids and fatty acids in peatland under varying oxygen concentrations

Author: Fatima Laggoun-Défarge, Martin Könneke, Arnaud Huguet, Travis B. Meador, Weichao Wu, Kai-Uwe Hinrichs, Sylvie Derenne, Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols (METIS), Université Pierre et Marie Curie - Paris 6 (UPMC)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO), Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Biogéosystèmes Continentaux - UMR7327, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), CNRS-INSU SNO Tourbières. Deutsche Forschungsgemeinschaft through Gottfried Wilhelm Leibniz Award awarded to K-U. Hinrichs (grant # HI 616-14), Université Pierre et Marie Curie - Paris 6 (UPMC)-École Pratique des Hautes Études (EPHE), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC)
Subjects: chemistry.chemical_classification, 010504 meteorology & atmospheric sciences, Stable isotope ratio, Stable-isotope probing, Heterotroph, 010502 geochemistry & geophysics, 01 natural sciences, Anoxic waters, chemistry, Biochemistry, Microbial population biology, [SDU]Sciences of the Universe [physics], 13. Climate action, Geochemistry and Petrology, Lipid biosynthesis, Environmental chemistry, Organic matter, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Acrotelm, 0105 earth and related environmental sciences
Abstract: International audience; Interpretations of the abundance and distribution of branched glycerol dialkyl glycerol tetraether (brGDGT) lipids have been increasingly applied to infer changes in paleoenvironment and to estimate terrigenous organic matter inputs into estuarine and marine sediments. However, only preliminary information is known regarding the ecology and physiology of the source organisms of these biomarkers. We assessed the production rates of brGDGTs under different redox conditions in peat, where these lipids are found in high concentrations, particularly at greater depths below the fluctuating water table. The incorporation of hydrogen relative to carbon into lipids observed in our dual stable isotope probing assay indicates that brGDGTs were produced by heterotrophic bacteria. Unexpectedly, incubations with stable isotope tracers of the surface horizon (5-20 cm) initiated under oxic conditions before turning suboxic and eventually anoxic exhibited up to one order of magnitude higher rates of brGDGT production (16-87 ng cm–3 y-1) relative to the deeper, anoxic zone (20- 35 cm; ca. 7 ng cm–3 y-1), and anoxic incubations of the surface horizon (< 3 ng cm–3 y-1). Turnover times of brGDGTs in the surface horizon ranged between 8 and 41 years in the incubations initiated under oxic conditions, in contrast to 123 to 742 years in anoxic incubations. As brGDGTs were actively produced during both anoxic incubations and those exposed to oxygen, we conclude that their source organisms are likely facultative aerobic heterotrophs that are particularly active in the peat acrotelm. Production rates of bacterial fatty acids (ca. 2 μg cm-3 y-1) were roughly two orders of magnitude higher than those of brGDGTs, suggesting that brGDGT producers are a minor constituent of the microbial community or that brGDGTs are a small component of the microbial cell membrane in comparison to fatty acids, despite the typically high brGDGT concentrations observed in peat. Multivariate analysis identified two branched fatty acids that shared a similar production pattern as brGDGTs among the experimental treatments and may be associated with brGDGT biosynthesis.
Published: 2017

42. Active tectonics of the Calabrian subduction revealed by new multi-beam bathymetric data and high-resolution seismic profiles in the Ionian Sea (Central Mediterranean)

Author: Benoît Loubrieu, Heidrun Kopp, Laurine San Pedro, César R. Ranero, Thierry Garlan, Stéphane Dominguez, Ingo Klaucke, Valentí Sallarès, Paul Wintersteller, Sebastian Krastel, Gerhard Bohrmann, Marc-André Gutscher, Yann Le Faou, Marzia Rovere, Sébastien Zaragosi, Bernard Mercier de Lépinay, European Commission, Domaines Océaniques (LDO), Centre National de la Recherche Scientifique (CNRS)-Institut d'écologie et environnement-Observatoire des Sciences de l'Univers-Université de Brest (UBO)-Institut national des sciences de l'Univers (INSU - CNRS), Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Christian-Albrechts-Universität zu Kiel (CAU), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Service Hydrographique et Océanographique de la Marine (SHOM), Ministère de la Défense, UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Ifremer - Pouzané, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS), Institute for marine sciences, Consiglio Nazionale delle Ricerche [Roma] (CNR), Géoazur (GEOAZUR 7329), Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Institució Catalana de Recerca i Estudis Avançats (ICREA), Unitat de Tecnologia Marina (UTM), Centre Mediterrani d'Investigacions Marines I ambientals, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS), GEOMAR - Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Environnements et Paléoenvironnements OCéaniques (EPOC), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Géosciences Marines (GM), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)
Subjects: seismic profiles, Accretionary wedge, 010504 meteorology & atmospheric sciences, bathymetry, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Escarpment, Active fault, Fault (geology), 010502 geochemistry & geophysics, Clastic wedge, 01 natural sciences, Geochemistry and Petrology, Eurasia-Africa plate boundary, Earth and Planetary Sciences (miscellaneous), Active faults, 14. Life underwater, active faults, accretionary wedge, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Subduction, Seismic profiles, Seafloor spreading, Geophysics, Sinistral and dextral, Space and Planetary Science, Bathymetry, subduction, Geology, Seismology
Abstract: Gutscher, Marc-André ... et al.-- 12 pages, 14 figures, 2 appendices, The detailed morphology and internal structure of the Calabrian accretionary wedge and adjacent Eastern Sicily margin are imaged in unprecedented detail by a combined dataset of multi-beam bathymetry and high-resolution seismic profiles. The bathymetric data represent the results of 6 recent marine geophysical surveys since 2010 as well as a compilation of earlier surveys presented as a 2 arc-sec (60 m) grid. Several distinct morpho-tectonic provinces are identified including: the deeply incised Malta–Hyblean Escarpment, numerous submarine canyons, broad regions of relatively flat seafloor dominated by fields of sediment waves, the gently undulating anticlinal fold-and-thrust belts of the external Calabrian accretionary wedge and the adjacent portion of the Western Mediterranean Ridge. The Calabrian arc can be divided into 4 domains (from SE to NW): 1) the undeformed Ionian abyssal plain, 2) the external evaporitic wedge, 3) the internal clastic wedge, 4) the Calabrian backstop (Variscan crystalline basement). The Calabrian accretionary wedge can also be divided laterally into two major lobes, the NE- and the SW lobes, and two minor lobes. The kinematics of the limit between the two major lobes is investigated and shown to be sinistral in the external (evaporitic) wedge. A network of radial slip lines within the southernmost external wedge unequivocally demonstrate ongoing dextral displacement of a rigid indenter (representing the corner of the clastic wedge) into the evaporitic wedge thereby confirming the geodynamic model of an active lateral slab tear fault here off eastern Sicily. The slab tear produces a series of major sub-parallel dextral strike-slip faults offshore Mt. Etna and south of the Straits of Messina consistent with the relative motions between Calabria and the Peloritan domain (NE Sicily). Abundant strike-slip faulting, and wide-spread folding and thrusting observed throughout the entire accretionary wedge, indicate regional shortening between the Ionian abyssal plain (foreland) and the Calabrian–Peloritan backstop caused by active subduction, We acknowledge INSU for funding related to the CIRCEE cruise and the European Union 7th Framework project ASTARTE, grant #603839, on Tsunami Hazard in Europe for support to MAG
Published: 2017

43. Assessing the carbon assimilation and production of benthic archaeal lipid biomarkers using lipid-RIP

Author: Marcus Elvert, Martin Könneke, Kevin W. Becker, Julius S. Lipp, Sarah Coffinet, Kai-Uwe Hinrichs, Thomas W. Evans, Verena B Heuer, Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Deutsche Forschungsgemeinschaft, European Research Council, Universität Bremen, Université de Rennes (UR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), and Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, biology, Chemistry, Methanogenesis, Heterotroph, 010502 geochemistry & geophysics, biology.organism_classification, 01 natural sciences, Mediterranean sea, Water column, 13. Climate action, Geochemistry and Petrology, Benthic zone, Environmental chemistry, Lipid biosynthesis, 14. Life underwater, Autotroph, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Archaea
Abstract: Distributional patterns of intact polar lipids (IPLs) suggest that archaea are abundant in marine subsurface sediments. However, the production of archaeal lipids remains largely unresolved. We performed a lipid radioisotope probing (lipid-RIP) experiment using 14C-bicarbonate and 2-14C-acetate with surface and methanogenic marine sediments from the Rhone delta (Mediterranean Sea) to investigate mechanisms of carbon assimilation and to assess biomass production of benthic archaea. The direct determination of carbon assimilation rates into diagnostic IPLs in the experiments with 14C-bicarbonate were up to 9 times higher than in the incubations with 2-14C-acetate, implying that autotrophy is an important carbon pathway for the benthic archaea in the Rhone delta sediments. Production rates of polyglycosidic archaeols (AR) were one to two orders of magnitude higher than those of mono- and polyglycosidic glycerol dialkyl glycerol tetraethers (GDGTs), suggesting that the former IPLs are good biomarkers for active benthic archaea in marine sediments. In contrast, the low production rates of the monoglycosidic AR and GDGTs, indicate that a large fraction of these IPLs may represent fossil sedimentary remains from the water column. Unexpectedly, the lipid production rates of AR and GDGT core lipids (CLs) were similar to those of polyglycosidic IPLs. Considering the relatively short period of incubation (21 days), this suggests that CLs may be actively synthesized by benthic archaea in marine sediments and are not exclusively formed from the degradation of IPL precursors.
Published: 2019

44. Recent climatic and anthropogenic impacts on endemic species in southwestern Morocco

Author: Zhao, Xueqin, Dupont, Lydie, Kölling, Martin, Reddad, Hanane, Groeneveld, Jeroen, Ain-Lhout, Fatima Zohra, Bouimetarhan, Ilham, Kaniewski, David, Marriner, Nick, Cheddadi, Rachid, Morhange, Christophe, Bretschneider, Joachim, Jans, Greta, Otto, Thierry, Luce, Frédéric, Van Campo, Elise, Department of Geosciences, University of Bremen, Université SMS Beni Mellal, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire Chrono-environnement - UFC (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Laboratoire Dynamique de la Biodiversité (LADYBIO), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), CNRS - ORSTOM Paléohydrologie, Paléoclimatique Continentales, Centre National de la Recherche Scientifique (CNRS), Department of Geosciences [Bremen], Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Chrono-environnement - CNRS - UBFC (UMR 6249) (LCE), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Mediterranean climate, 010506 paleontology, Archeology, 010504 meteorology & atmospheric sciences, media_common.quotation_subject, Biodiversity, Climate change, medicine.disease_cause, 01 natural sciences, Pollen, medicine, Endemism, Ecology, Evolution, Behavior and Systematics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, media_common, Global and Planetary Change, Geology, 15. Life on land, [SDE.ES]Environmental Sciences/Environmental and Society, Geography, Desertification, 13. Climate action, North Atlantic oscillation, Threatened species, Physical geography
Abstract: Morocco is an area subject to recurrent severe droughts, desertification and an increasing land degradation. It is within a Mediterranean hotspot of biodiversity as it harbors many threatened endemic species such as the argan tree (Argania spinosa). In this context, past climate records are needed to analyze the impact of climate variability on the occurrence and future persistence of these endemic species. In order to evaluate the impact of past climate changes on the endemic Argan tree in southern Morocco, we reconstructed its modern range using an extensive pollen dataset. The modern pollen distribution off southwestern Morocco was then utilized to interpret the high-resolution pollen record with complementary micro-charcoal and XRF element records from a marine sediment core GeoB8601-3 off Cape Ghir in southwestern Morocco covering the last three millennia. This multi-proxy study has shown clear evidence of wetter conditions resulting in higher fluvial input which could be correlated with a negative mode of the North Atlantic Oscillation (NAO), in contrast to the published pollen and XRF element records from another nearby core that showed limited effect of climate changes. On the other hand, clear opposite trend between the pollen occurrences of Argania spinosa and the fire frequency was observed throughout our fossil record. The increase of Argania spinosa pollen occurrences, along with herbaceous taxa, and lower fire frequency might suggest an increase in human impact on the landscape leading to a sparse vegetation cover and subsequently increased erosion. The reconstructed pollen-based vegetation, micro-charcoal-based fire activities and geochemical changes in our marine record suggest interplay of climate and anthropogenic effects on the landscape.
Published: 2019

45. Provenance of Bengal Shelf Sediments: 1. Mineralogy and Geochemistry of Silt

Author: Giovanni Coletti, Laura Borromeo, Annette Hahn, Christian France-Lanord, Eduardo Garzanti, Sergio Andò, Laboratory for Provenance Studies, Department of Earth and Environmental Sciences, University of Milano-Bicocca, Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), Dipartimento di Scienze Geologiche e Geotecnologie, Centre de Recherches Pétrographiques et Géochimiques (CRPG), Université de Lorraine (UL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Borromeo, L, Ando, S, France-Lanord, C, Coletti, G, Hahn, A, and Garzanti, E
Subjects: Provenance, lcsh:QE351-399.2, 010504 meteorology & atmospheric sciences, Geochemistry, bay of bengal, Mineralogy, Detritus (geology), [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, benthic foraminifera, engineering.material, Silt, 010502 geochemistry & geophysics, 01 natural sciences, raman spectroscopy, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Ganga-Brahmaputra river system, provenance analysis, Plagioclase, 14. Life underwater, fallacy of laser granulometry, 0105 earth and related environmental sciences, Provenance analysi, Ganga, lcsh:Mineralogy, himalayan orogen, Sediment, Heavy mineral, Geology, Geotechnical Engineering and Engineering Geology, 6. Clean water, heavy minerals, ganga–brahmaputra river system, sieving of fine silt, 13. Climate action, Granulometry, [SDU]Sciences of the Universe [physics], BENGAL, engineering, Suspended load, Brahmaputra river system
Abstract: This article illustrates a multi-technique frontier approach for the provenance study of silt-size sediments. The mineralogical composition of low-density and heavy-mineral fractions of four samples of fine to very coarse silt deposited on the Bengal shelf was analyzed separately for six different grain-size classes by combining grain counting under an optical microscope, Raman spectroscopy, and X-ray diffraction. The geochemical composition was determined on both bulk-sediment samples and on their &lt, 5-&mu, m classes. Such a &ldquo, multiple-window&rdquo, approach allowed capturing the full mineralogical information contained in each sample, as well as the size-dependent intra-sample variability of all compositional parameters. The comparison between grain-size distributions obtained by different methods highlighted a notable fallacy of laser granulometry, which markedly overestimated the size of the finest mode represented by fine silt and clay. As a test case, we chose to investigate sediments of the Bengal shelf, where detritus is fed from the Meghna estuary, formed by the joint Ganga and Brahmaputra Rivers and representing the largest single entry point of sediment in the world&rsquo, s oceans. The studied samples show the typical fingerprint of orogenic detritus produced by focused erosion of collision orogens. Bengal shelf silt is characterized by a feldspatho-quartzose (F-Q) composition with a Q/F ratio decreasing from 3.0 to 1.7 with increasing grain size, plagioclase prevailing over K-feldspar, and rich transparent-heavy-mineral assemblages including mainly amphibole with epidote, and minor garnet and pyroxene. Such a detrital signature compares very closely with Brahmaputra suspended load, but mineralogical and geochemical parameters, including the anomalous decrease of the Q/F ratio with increasing grain size, consistently indicate more significant Ganga contribution for cohesive fine silt. The accurate quantitative characterization of different size fractions of Bengal shelf sediments represents an essential step to allow comparison of compositional signatures characterizing different segments of this huge source-to-sink system, from fluvial and deltaic sediments of the Himalayan foreland basin and Bengal shelf to the Bengal Fan.
Published: 2019

46. Observational Needs Supporting Marine Ecosystems Modeling and Forecasting: From the Global Ocean to Regional and Coastal Systems

Author: Antonietta Capotondi, Michael Jacox, Chris Bowler, Maria Kavanaugh, Patrick Lehodey, Daniel Barrie, Stephanie Brodie, Samuel Chaffron, Wei Cheng, Daniela F. Dias, Damien Eveillard, Lionel Guidi, Daniele Iudicone, Nicole S. Lovenduski, Janet A. Nye, Ivonne Ortiz, Douglas Pirhalla, Mercedes Pozo Buil, Vincent Saba, Scott Sheridan, Samantha Siedlecki, Aneesh Subramanian, Colomban de Vargas, Emanuele Di Lorenzo, Scott C. Doney, Albert J. Hermann, Terrence Joyce, Mark Merrifield, Arthur J. Miller, Fabrice Not, Stephane Pesant, NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Institut de biologie de l'ENS Paris (IBENS), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Marine Ecosystems Modeling and Monitoring by Satellites (MEMMS), CLS, Environmental Research Division [USA], Southwest Fisheries Science Center (SWFSC), NOAA National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA)-NOAA National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA), Laboratoire des Sciences du Numérique de Nantes (LS2N), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), The George Washington University (GW), Combinatoire et Bioinformatique (COMBI), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Stazione Zoologica Anton Dohrn (SZN), Northeast Fisheries Science Center (NEFSC), Evolution des Protistes et Ecosystèmes Pélagiques (EPEP), Adaptation et diversité en milieu marin (AD2M), Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), ECOlogy of MArine Plankton (ECOMAP), Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), School of Earth and Atmospheric Sciences [Atlanta], Georgia Institute of Technology [Atlanta], Department of Marine Chemistry and Geochemistry (WHOI), Woods Hole Oceanographic Institution (WHOI), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Institut de biologie de l'ENS Paris (UMR 8197/1024) (IBENS), Département de Biologie - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), and Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, lcsh:QH1-199.5, Climate change, Ocean Engineering, Aquatic Science, Biology, lcsh:General. Including nature conservation, geographical distribution, Oceanography, 01 natural sciences, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Ecosystem model, Marine ecosystem, Ecosystem, genetics, 14. Life underwater, Predictability, marine ecosystems, acoustics, lcsh:Science, Recreation, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Water Science and Technology, Apex predator, Global and Planetary Change, business.industry, [SDE.IE]Environmental Sciences/Environmental Engineering, 010604 marine biology & hydrobiology, modeling and forecasting, Environmental resource management, 15. Life on land, seascapes, 13. Climate action, lcsh:Q, Landscape ecology, business
Abstract: International audience; Many coastal areas host rich marine ecosystems and are also centers of economic activities, including fishing, shipping and recreation. Due to the socioeconomic and ecological importance of these areas, predicting relevant indicators of the ecosystem state on sub-seasonal to interannual timescales is gaining increasing attention. Depending on the application, forecasts may be sought for variables and indicators spanning physics (e.g., sea level, temperature, currents), chemistry (e.g., nutrients, oxygen, pH), and biology (from viruses to top predators). Many components of the marine ecosystem are known to be influenced by leading modes of climate variability, which provide a physical basis for predictability. However, prediction capabilities remain limited by the lack of a clear understanding of the physical and biological processes involved, as well as by insufficient observations for forecast initialization and verification. The situation is further complicated by the influence of climate change on ocean conditions along coastal areas, including sea level rise, increased stratification, and shoaling of oxygen minimum zones. Observations are thus vital to all aspects of marine forecasting: statistical and/or dynamical model development, forecast initialization, and forecast validation, each of which has different observational requirements, which may be also specific to the study region. Here, we use examples from United States (U.S.) coastal applications to identify and describe the key requirements for an observational network that is needed to facilitate improved process understanding, as well as for sustaining operational ecosystem forecasting. We also describe new holistic observational approaches, e.g., approaches based on acoustics, inspired by Tara Oceans or by landscape ecology, which have the potential to support and expand ecosystem modeling and forecasting activities by bridging global and local observations.
Published: 2019

47. Atlantic Meridional Overturning Circulation: Observed Transport and Variability

Author: Eleanor Frajka-Williams, Isabelle J. Ansorge, Johanna Baehr, Harry L. Bryden, Maria Paz Chidichimo, Stuart A. Cunningham, Gokhan Danabasoglu, Shenfu Dong, Kathleen A. Donohue, Shane Elipot, Patrick Heimbach, N. Penny Holliday, Rebecca Hummels, Laura C. Jackson, Johannes Karstensen, Matthias Lankhorst, Isabela A. Le Bras, M. Susan Lozier, Elaine L. McDonagh, Christopher S. Meinen, Herlé Mercier, Bengamin I. Moat, Renellys C. Perez, Christopher G. Piecuch, Monika Rhein, Meric A. Srokosz, Kevin E. Trenberth, Sheldon Bacon, Gael Forget, Gustavo Goni, Dagmar Kieke, Jannes Koelling, Tarron Lamont, Gerard D. McCarthy, Christian Mertens, Uwe Send, David A. Smeed, Sabrina Speich, Marcel van den Berg, Denis Volkov, Chris Wilson, National Oceanography Centre (NOC), Department of Oceanography [Cape Town], University of Cape Town, Universität Hamburg (UHH), Istituto di Scienze Marine [La Spezia] (CNR-ISMAR-SP), Istituto di Science Marine (ISMAR ), Consiglio Nazionale delle Ricerche (CNR)-Consiglio Nazionale delle Ricerche (CNR), Centre for Applied Internet Research (CAIR), Wrexham Glyndŵr University, National Center for Atmospheric Research [Boulder] (NCAR), National Oceanic and Atmospheric Administration (NOAA), National Oceanography Centre [Southampton] (NOC), University of Southampton, Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Laboratoire de physique des océans (LPO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Woods Hole Oceanographic Institution (WHOI), Institut für Umweltphysik [Bremen] (IUP), Universität Bremen, Massachusetts Institute of Technology (MIT), Scripps Institution of Oceanography (SIO), University of California [San Diego] (UC San Diego), and University of California-University of California
Subjects: 0106 biological sciences, observing systems, lcsh:QH1-199.5, 010504 meteorology & atmospheric sciences, Ocean Engineering, Zonal and meridional, lcsh:General. Including nature conservation, geographical distribution, Aquatic Science, Oceanography, 01 natural sciences, Deep sea, moorings, 14. Life underwater, lcsh:Science, Sea level, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Water Science and Technology, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Global and Planetary Change, 010604 marine biology & hydrobiology, circulation variability, carbon storage, meridional overturning circulation, Sea surface temperature, thermohaline circulation, 13. Climate action, Climatology, Environmental science, lcsh:Q, Thermohaline circulation, Climate model, ocean heat transport, Ocean heat content, Hydrography
Abstract: The Atlantic Meridional Overturning Circulation (AMOC) extends from the Southern Ocean to the northern North Atlantic, transporting heat northwards throughout the South and North Atlantic, and sinking carbon and nutrients into the deep ocean. Climate models indicate that changes to the AMOC both herald and drive climate shifts. Intensive trans-basin AMOC observational systems have been put in place to continuously monitor meridional volume transport variability, and in some cases, heat, freshwater and carbon transport. These observational programs have been used to diagnose the magnitude and origins of transport variability, and to investigate impacts of variability on essential climate variables such as sea surface temperature, ocean heat content and coastal sea level. AMOC observing approaches vary between the different systems, ranging from trans-basin arrays (OSNAP, RAPID 26◦N, 11◦S, SAMBA 34.5◦S) to arrays concentrating on western boundaries (e.g., RAPID WAVE, MOVE 16◦N). In this paper, we outline the different approaches (aims, strengths and limitations) and summarize the key results to date. We also discuss alternate approaches for capturing AMOC variability including direct estimates (e.g., using sea level, bottom pressure, and hydrography from autonomous profiling floats), indirect estimates applying budgetary approaches, state estimates or ocean reanalyses, and proxies. Based on the existing observations and their results, and the potential of new observational and formal synthesis approaches, we make suggestions as to how to evaluate a comprehensive, future-proof observational network of the AMOC to deepen our understanding of the AMOC and its role in global climate.
Published: 2019

48. Seafloor evidence for pre-shield volcanism above the Tristan da Cunha mantle plume

Author: Anne Strack, Wilfried Jokat, Wolfram Geissler, Graeme Eagles, Janina Kammann, Marion Jegen, Paul Wintersteller, Marcia Maia, Antje Schloemer, Alfred Wegener Institute for Polar and Marine Research (AWI), Faculty of Geosciences, University of Bremen, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Laboratoire Géosciences Océan (LGO), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Geoscience and Natural Resource Management, København Universitet, Danmark, Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Ludwig-Maximilians-Universität München (LMU), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), and Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Science, Seamount, General Physics and Astronomy, Volcanology, 010502 geochemistry & geophysics, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, Mantle plume, Article, Paleontology, 14. Life underwater, lcsh:Science, Submarine volcano, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, geography, Multidisciplinary, geography.geographical_feature_category, Tectonics, Fracture zone, Geology, General Chemistry, Seafloor spreading, Oceanic core complex, Submarine eruption, Geophysics, Volcano, 13. Climate action, lcsh:Q
Abstract: Tristan da Cunha is assumed to be the youngest subaerial expression of the Walvis Ridge hot spot. Based on new hydroacoustic data, we propose that the most recent hot spot volcanic activity occurs west of the island. We surveyed relatively young intraplate volcanic fields and scattered, probably monogenetic, submarine volcanoes with multibeam echosounders and sub-bottom profilers. Structural and zonal GIS analysis of bathymetric and backscatter results, based on habitat mapping algorithms to discriminate seafloor features, revealed numerous previously-unknown volcanic structures. South of Tristan da Cunha, we discovered two large seamounts. One of them, Isolde Seamount, is most likely the source of a 2004 submarine eruption known from a pumice stranding event and seismological analysis. An oceanic core complex, identified at the intersection of the Tristan da Cunha Transform and Fracture Zone System with the Mid-Atlantic Ridge, might indicate reduced magma supply and, therefore, weak plume-ridge interaction at present times., Here, the authors combine bathymetry and sediment echosound data to present a submarine, volcanic map of the Tristan de la Cunha region. They find that the youngest volcanic expression of the Tristan de la Cunha mantle plume is currently located to the (south-) west of the island.
Published: 2019

49. Interhemispheric radio-astrochronological calibration of the time scales from the Andean and the Tethyan areas in the Valanginian–Hauterivian (Early Cretaceous)

Author: Marina Lescano, Heiko Pälike, Julieta Omarini, Thomas Frederichs, Peter F. Rawson, Maisa Tunik, Stéphane Reboulet, Anna-Leah Nickl, Mathieu Martinez, Mark D. Schmitz, Andrea Concheyro, Nicolas Noclin, Henning Kuhnert, Beatriz Aguirre-Urreta, Victor A. Ramos, Universidad de Buenos Aires [Buenos Aires] (UBA), Géosciences Rennes (GR), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Boise State University, Universidad Nacional de Río Negro (UNRN), University College of London [London] (UCL), University of Hull [United Kingdom], Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Consejo Nacional de Investigaciones Científicas y Técnicas, Agencia Nacional de Promoción Científica y Tecnológica, H2020 European Research Council, EXC 309/FZT 15, Deutsche Forschungsgemeinschaft, UBA, Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, Calibration (statistics), Geochronology, Cyclostratigraphy, Biostratigraphy, Structural basin, Western Gondwana, 010502 geochemistry & geophysics, 01 natural sciences, Ciencias de la Tierra y relacionadas con el Medio Ambiente, Paleontology, Stage (stratigraphy), Neuquén Basin, Geología, 14. Life underwater, Tethys, Geologia, 0105 earth and related environmental sciences, Geology, Cretaceous, 13. Climate action, [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, CIENCIAS NATURALES Y EXACTAS
Abstract: Fil: Tunik, Maisa A. Universidad Nacional de Río Negro. Instituto de Investigación en Paleobiología y Geología. Río Negro; Argentina Fil: Tunik, Maisa A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación en Paleobiología y Geología. Río Negro; Argentina Fil: Aguirre Urreta, Beatriz. Universidad de Buenos Aires. Instituto de Estudios Andinos Don Pablo Groeber. Buenos Aires; Argentina. Fil: Aguirre Urreta, Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Estudios Andinos Don Pablo Groeber. Buenos Aires; Argentina. Fil: Martinez, Mathieu. Universität Bremen. MARUM – Center for Marine Environmental Sciences. Bremen; Germany. Fil: Schmitz, Mark. Boise State University. Department of Geosciences. Idaho; USA. Fil: Lescano, Marina. Universidad Nacional de Río Negro. Instituto de Investigación en Paleobiología y Geología. Río Negro; Argentina Fil: Lescano, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación en Paleobiología y Geología. Río Negro; Argentina Fil: Omarini, Julieta. Universidad Nacional de Río Negro. Instituto de Investigación en Paleobiología y Geología. Río Negro; Argentina Fil: Omarini, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación en Paleobiología y Geología. Río Negro; Argentina Fil: Kuhnert, Henning. Universität Bremen. MARUM – Center for Marine Environmental Sciences. Bremen; Germany. Fil: Concheyro, Andrea. Universidad de Buenos Aires. Instituto de Estudios Andinos Don Pablo Groeber. Buenos Aires; Argentina. Fil: Concheyro, Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Estudios Andinos Don Pablo Groeber. Buenos Aires; Argentina. Fil: Rawson, Peter F. University of Hull. School of Environmental Sciences. Hull; UK. Fil: Rawson, Peter F. University College London. Department of Earth Sciences. London; UK. Fil: Ramos, Victor A. Universidad de Buenos Aires. Instituto de Estudios Andinos Don Pablo Groeber. Buenos Aires; Argentina. Fil: Ramos, Victor A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Estudios Andinos Don Pablo Groeber. Buenos Aires; Argentina. Fil: Reboulet, Stéphane. Université de Lyon, UCBL, ENSL, CNRS, LGL TPE, Bâtiment Géode. Villeurbanne; France. Fil: Noclin, Nicolas. Université de Lyon, UCBL, ENSL, CNRS, LGL TPE, Bâtiment Géode. Villeurbanne; France. Fil: Frederichs, Thomas. Universität Bremen. MARUM – Center for Marine Environmental Sciences. Bremen; Germany. Fil: Nickl, Anna L. Universität Bremen. MARUM – Center for Marine Environmental Sciences. Bremen; Germany. Fil: Pälike, Heiko. Universität Bremen. MARUM – Center for Marine Environmental Sciences. Bremen; Germany. An integrated radio-astrochronological framework of the Agrio Formation in the Andean Neuquén Basin of westcentral Argentina provides new constraints on the age and the duration of the late Valanginian through Hauterivian stratigraphic interval. A CA-ID TIMS U-Pb age of 126.97 ± 0.04(0.07)[0.15] Ma is presented here from the upper Hauterivian Agua de la Mula Member of the Agrio Formation. Biostratigraphic data from ammonoids and calcareous nannofossils and this high precision new radioisotopic age, together with three former ones from the same Agrio Formation are combined with new astrochronological data in the Andes. These are correlated with modern cyclostratigraphic studies in the classical sections of the Mediterranean Province of the Tethys, supporting detailed interhemispheric correlations for the Early Cretaceous. We also provide new δ13C data from the Agrio Formation which are compared with records from the classic Tethyan sections. According to our calibration, the minimum in the values in the mid-Hauterivian appears to be synchronous and, thus, another important stratigraphic marker for global correlation. A new duration of 5.21 ± 0.08 myr is calculated for the Hauterivian Stage, starting at 131.29 ± 0.19 Ma and ending at 126.08 ± 0.19 Ma. The difference between the duration of the Hauterivian in GTS2016 and in this study is 1.32 myr while the base and top of the GTS2016 Hauterivian differ respectively by 3.40 and 4.69 myr.
Published: 2019

50. The roles of climate and human land-use in the late Holocene rainforest crisis of Central Africa

Author: Charlotte Skonieczny, Alberto Borges, Luc André, Gesine Mollenhauer, Germain Bayon, Laurence Monin, Bernard Dennielou, Thibault Lambert, Lydie M Dupont, Emmanuel Ponzevera, Enno Schefuß, Unité de recherche Géosciences Marines (Ifremer) (GM), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Royal Museum for Central Africa [Tervuren] (RMCA), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Université de Liège, IFREMER, Université de Lausanne, Institut des Sciences de la Terre, bâtiment Géopolis, CH-1015, Lausanne, Switzerland, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Géosciences Paris Sud (GEOPS), and Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Climate change, Submarine canyon, Rainforest, 010502 geochemistry & geophysics, 01 natural sciences, law.invention, Geochemistry and Petrology, Deforestation, law, Earth and Planetary Sciences (miscellaneous), suspended particulates, deforestation, Radiocarbon dating, ComputingMilieux_MISCELLANEOUS, Holocene, 0105 earth and related environmental sciences, 2. Zero hunger, geography, geography.geographical_feature_category, Vegetation, 15. Life on land, Geophysics, Congo Basin, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, Erosion, neodymium isotopes, Physical geography, ENSO, human land-use, Geology
Abstract: There is increasing evidence that abrupt vegetation shifts and large-scale erosive phases occurred in Central Africa during the third millennium before present. Debate exists as to whether these events were caused by climate change and/or intensifying human activities related to the Bantu expansion. In this study, we report on a multi-proxy investigation of a sediment core (KZR-23) recovered from the Congo submarine canyon. Our aim was to reconstruct climate, erosion and vegetation patterns in the Congo Basin for the last 10,000 yrs, with a particular emphasis on the late Holocene period. Samples of modern riverine suspended particulates were also analyzed to characterize sediment source geochemical signatures from across the Congo watershed. We find that a sudden increase of bulk sediment aluminium-to-potassium (Al/K) ratios and initial radiocarbon ages of bulk organic matter occurred after 2,200 yrs ago, coincident with a pollen-inferred vegetation change suggesting forest retreat and development of savannas. Although hydrogen isotope compositions of plant waxes (δDwax) do not reveal a substantial hydroclimate shift during this period, neodymium isotopes and rare earth elements in detrital fractions indicate provenance changes for the sediment exported from the Congo Basin at that time, hence suggesting a reorganization of spatial rainfall patterns across Central Africa during this event. Taken together, these findings provide evidence for changing landscapes in Central Africa from about 2,200 yrs ago, associated with synchronous events of vegetation changes and enhanced erosion of pre-aged and highly weathered soils. These events coincided remarkably well with the arrival of Iron Age communities into the rainforest, as inferred from comparison to regional archaeological syntheses. While the human impact on the environment remains difficult to quantify at the scale of the vast Congo Basin, we tentatively propose that strengthening of El Nino-Southern Oscillation (ENSO) variability at that time played a key role in triggering the observed environmental changes, and possibly acted as a driver for the eastward migration of Bantu-speaking peoples across Central Africa.
Published: 2019

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