192 results on '"Rehder, Gregor"'
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2. Mögliche Beiträge geologischer und mariner Kohlenstoffspeicher zur Dekarbonisierung
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Oschlies, Andreas, Mengis, Nadine, Rehder, Gregor, Schill, Eva, Thomas, Helmuth, Wallmann, Klaus, Zimmer, Martin, Brasseur, Guy P., editor, Jacob, Daniela, editor, and Schuck-Zöller, Susanne, editor
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- 2023
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3. Ideas and perspectives: A strategic assessment of methane and nitrous oxide measurements in the marine environment
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Wilson, Samuel T, Al-Haj, Alia N, Bourbonnais, Annie, Frey, Claudia, Fulweiler, Robinson W, Kessler, John D, Marchant, Hannah K, Milucka, Jana, Ray, Nicholas E, Suntharalingham, Parv, Thornton, Brett F, Upstill-Goddard, Robert C, Weber, Thomas S, Arévalo-Martínez, Damian L, Bange, Hermann W, Benway, Heather M, Bianchi, Daniele, Borges, Alberto V, Chang, Bonnie X, Crill, Patrick M, del Valle, Daniela A, Farías, Laura, Joye, Samantha B, Kock, Annette, Labidi, Jabrane, Manning, Cara C, Pohlman, John W, Rehder, Gregor, Sparrow, Katy J, Tortell, Philippe D, Treude, Tina, Valentine, David L, Ward, Bess B, Yang, Simon, and Yurganov, Leonid N
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Life Below Water ,Earth Sciences ,Environmental Sciences ,Biological Sciences ,Meteorology & Atmospheric Sciences - Abstract
In the current era of rapid climate change, accurate characterization of climate-relevant gas dynamics-namely production, consumption, and net emissions-is required for all biomes, especially those ecosystems most susceptible to the impact of change. Marine environments include regions that act as net sources or sinks for numerous climateactive trace gases including methane (CH4) and nitrous oxide (N2O). The temporal and spatial distributions of CH4 and N2O are controlled by the interaction of complex biogeochemical and physical processes. To evaluate and quantify how these mechanisms affect marine CH4 and N2O cycling requires a combination of traditional scientific disciplines including oceanography, microbiology, and numerical modeling. Fundamental to these efforts is ensuring that the datasets produced by independent scientists are comparable and interoperable. Equally critical is transparent communication within the research community about the technical improvements required to increase our collective understanding of marine CH4 and N2O. A workshop sponsored by Ocean Carbon and Biogeochemistry (OCB) was organized to enhance dialogue and collaborations pertaining to marine CH4 and N2O. Here, we summarize the outcomes from the workshop to describe the challenges and opportunities for near-future CH4 and N2O research in the marine environment.
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- 2020
4. Metrology for pH Measurements in Brackish Waters-Part 1: Extending Electrochemical pH(T) Measurements of TRIS Buffers to Salinities 5-20
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Mueller, Jens D, Bastkowski, Frank, Sander, Beatrice, Seitz, Steffen, Turner, David R, Dickson, Andrew G, and Rehder, Gregor
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Harned cell ,traceability ,primary standard ,TRIS ,pH ,total scale ,brackish water ,seawater ,Oceanography ,Ecology - Published
- 2018
5. Metrology for pH Measurements in Brackish Waters—Part 1: Extending Electrochemical pHT Measurements of TRIS Buffers to Salinities 5–20
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Müller, Jens D, Bastkowski, Frank, Sander, Beatrice, Seitz, Steffen, Turner, David R, Dickson, Andrew G, and Rehder, Gregor
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Earth Sciences ,Geochemistry ,Harned cell ,traceability ,primary standard ,TRIS ,pH ,total scale ,brackish water ,seawater ,Oceanography ,Ecology ,Geology - Published
- 2018
6. Carbon release and transformation from coastal peat deposits controlled by submarine groundwater discharge : a column experiment study
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Kreuzburg, Matthias, Rezanezhad, Fereidoun, Milojevic, Tatjana, Voss, Maren, Gosch, Lennart, Liebner, Susanne, Van Cappellen, Philippe, and Rehder, Gregor
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- 2020
7. Effects of climate change on methane emissions from seafloor sediments in the Arctic Ocean: A review
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James, Rachael H, Bousquet, Philippe, Bussmann, Ingeborg, Haeckel, Matthias, Kipfer, Rolf, Leifer, Ira, Niemann, Helge, Ostrovsky, Ilia, Piskozub, Jacek, Rehder, Gregor, Treude, Tina, Vielstädte, Lisa, and Greinert, Jens
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Climate Action ,Life Below Water ,Earth Sciences ,Environmental Sciences ,Biological Sciences ,Marine Biology & Hydrobiology - Published
- 2016
8. Global Carbon Budget 2023
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Friedlingstein, Pierre, primary, O'Sullivan, Michael, additional, Jones, Matthew W., additional, Andrew, Robbie M., additional, Bakker, Dorothee C. E., additional, Hauck, Judith, additional, Landschützer, Peter, additional, Le Quéré, Corinne, additional, Luijkx, Ingrid T., additional, Peters, Glen P., additional, Peters, Wouter, additional, Pongratz, Julia, additional, Schwingshackl, Clemens, additional, Sitch, Stephen, additional, Canadell, Josep G., additional, Ciais, Philippe, additional, Jackson, Robert B., additional, Alin, Simone R., additional, Anthoni, Peter, additional, Barbero, Leticia, additional, Bates, Nicholas R., additional, Becker, Meike, additional, Bellouin, Nicolas, additional, Decharme, Bertrand, additional, Bopp, Laurent, additional, Brasika, Ida Bagus Mandhara, additional, Cadule, Patricia, additional, Chamberlain, Matthew A., additional, Chandra, Naveen, additional, Chau, Thi-Tuyet-Trang, additional, Chevallier, Frédéric, additional, Chini, Louise P., additional, Cronin, Margot, additional, Dou, Xinyu, additional, Enyo, Kazutaka, additional, Evans, Wiley, additional, Falk, Stefanie, additional, Feely, Richard A., additional, Feng, Liang, additional, Ford, Daniel J., additional, Gasser, Thomas, additional, Ghattas, Josefine, additional, Gkritzalis, Thanos, additional, Grassi, Giacomo, additional, Gregor, Luke, additional, Gruber, Nicolas, additional, Gürses, Özgür, additional, Harris, Ian, additional, Hefner, Matthew, additional, Heinke, Jens, additional, Houghton, Richard A., additional, Hurtt, George C., additional, Iida, Yosuke, additional, Ilyina, Tatiana, additional, Jacobson, Andrew R., additional, Jain, Atul, additional, Jarníková, Tereza, additional, Jersild, Annika, additional, Jiang, Fei, additional, Jin, Zhe, additional, Joos, Fortunat, additional, Kato, Etsushi, additional, Keeling, Ralph F., additional, Kennedy, Daniel, additional, Klein Goldewijk, Kees, additional, Knauer, Jürgen, additional, Korsbakken, Jan Ivar, additional, Körtzinger, Arne, additional, Lan, Xin, additional, Lefèvre, Nathalie, additional, Li, Hongmei, additional, Liu, Junjie, additional, Liu, Zhiqiang, additional, Ma, Lei, additional, Marland, Greg, additional, Mayot, Nicolas, additional, McGuire, Patrick C., additional, McKinley, Galen A., additional, Meyer, Gesa, additional, Morgan, Eric J., additional, Munro, David R., additional, Nakaoka, Shin-Ichiro, additional, Niwa, Yosuke, additional, O'Brien, Kevin M., additional, Olsen, Are, additional, Omar, Abdirahman M., additional, Ono, Tsuneo, additional, Paulsen, Melf, additional, Pierrot, Denis, additional, Pocock, Katie, additional, Poulter, Benjamin, additional, Powis, Carter M., additional, Rehder, Gregor, additional, Resplandy, Laure, additional, Robertson, Eddy, additional, Rödenbeck, Christian, additional, Rosan, Thais M., additional, Schwinger, Jörg, additional, Séférian, Roland, additional, Smallman, T. Luke, additional, Smith, Stephen M., additional, Sospedra-Alfonso, Reinel, additional, Sun, Qing, additional, Sutton, Adrienne J., additional, Sweeney, Colm, additional, Takao, Shintaro, additional, Tans, Pieter P., additional, Tian, Hanqin, additional, Tilbrook, Bronte, additional, Tsujino, Hiroyuki, additional, Tubiello, Francesco, additional, van der Werf, Guido R., additional, van Ooijen, Erik, additional, Wanninkhof, Rik, additional, Watanabe, Michio, additional, Wimart-Rousseau, Cathy, additional, Yang, Dongxu, additional, Yang, Xiaojuan, additional, Yuan, Wenping, additional, Yue, Xu, additional, Zaehle, Sönke, additional, Zeng, Jiye, additional, and Zheng, Bo, additional
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- 2023
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9. A regional p CO2 climatology of the Baltic Sea from in situ p CO2 observations and a model-based extrapolation approach.
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Bittig, Henry C., Jacobs, Erik, Neumann, Thomas, and Rehder, Gregor
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EXTRAPOLATION ,CLIMATOLOGY ,CARBON dioxide ,ORTHOGONAL functions ,OCEAN temperature - Abstract
Ocean surface pCO 2 estimates are of great interest for the calculation of air–sea CO 2 fluxes, oceanic uptake of anthropogenic CO 2 , and eventually the Global Carbon Budget. They are accessible from direct observations, which are discrete in space and time and thus always sparse, or from biogeochemical models, which only approximate reality. Here, a combined method for the extrapolation of pCO 2 observations is presented that uses (1) model-based patterns of variability from an empirical orthogonal function (EOF) analysis of variability with (2) observational data to constrain EOF pattern amplitudes in (3) an ensemble approach, which locally adjusts the spatial scale of the mapping to the density of the observations. Thus, data-constrained, gap- and discontinuity-free mapped fields including local error estimates are obtained without the need for or dependence on ancillary data (e.g. satellite sea surface temperature maps). This extrapolation approach is generic in that it can be applied to any oceanic or coastal region covered by a suitable model and observations. It is used here to establish a regional pCO 2 climatology of the Baltic Sea (: 10.1594/PANGAEA.961119), largely based on ICOS-DE ship of opportunity (SOOP) Finnmaid surface pCO 2 observations between Lübeck-Travemünde (Germany) and Helsinki (Finland). The climatology can serve as improved input for atmosphere–ocean CO 2 flux estimation in this coastal environment. [ABSTRACT FROM AUTHOR]
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- 2024
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10. The contribution of zooplankton to methane supersaturation in the oxygenated upper waters of the central Baltic Sea
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Schmale, Oliver, Wäge, Janine, Mohrholz, Volker, Wasmund, Norbert, Gräwe, Ulf, Rehder, Gregor, Labrenz, Matthias, and Loick-Wilde, Natalie
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- 2018
11. Baltic Sea transparency from ships and satellites: centennial trends
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Kahru, Mati, Bittig, Henry, Elmgren, Ragnar, Fleming, Vivi, Lee, Zhongping, Rehder, Gregor, Suomen ympäristökeskus, and The Finnish Environment Institute
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climate variability ,Baltic Sea ,Ecology ,aikasarjat ,rehevöityminen ,vesi ,Secchi depth ,kd490 ,Aquatic Science ,chromophoric dissolved organic matter ,water transparency ,läpinäkyvyys ,Secchi-syvyys ,liuennut orgaaninen aines ,eutrophication ,merentutkimus ,Itämeri ,ilmasto ,näkösyvyys ,vaihtelu ,CDOM ,light attenuation ,meret ,Ecology, Evolution, Behavior and Systematics - Abstract
Water transparency can be measured with optical instruments and estimated with satellite sensors, but such measurements have been widely available for only a few decades. Estimates of water transparency using a white disk called a Secchi disk have been made for over a century and can be used to estimate long-term trends. However, historic in situ measurements of the Secchi depth (ZSd) were irregular in space and time and are difficult to interpret in regular time series due to biases introduced by changing locations and the timing of measurements. Satellite data time series, on the other hand, have consistent resolution in both space and time but cover too short a time to resolve climate-scale trends. We normalized historic ZSd measurements in the Baltic Sea with a satellite-derived mean climatology at 5 d temporal and 4 km spatial resolutions and created a merged time series of ZSd for the last century. The mean ZSd in the Baltic Sea from 1927-2020 decreased by 4.2 ± 0.6 m at a rate of 0.045 ± 0.06 m yr-1. Most of the change happened before 1987, and a further decrease was evident primarily in the satellite data during the 1998-2008 period. After 2008, no significant trend in ZSd and or the coefficient of diffuse light attenuation was detected in the Baltic Sea. However, in some sub-basins of the Baltic Sea, the decrease in ZSd continued even after that. The decrease in spectral water transparency in recent decades was highest in the 412 nm band, indicating an increase in the concentration of chromophoric dissolved organic matter.
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- 2022
12. Nutrient release and flux dynamics of CO2, CH4, and N2O in a coastal peatland driven by actively induced rewetting with brackish water from the Baltic Sea
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Pönisch, Daniel L., primary, Breznikar, Anne, additional, Gutekunst, Cordula N., additional, Jurasinski, Gerald, additional, Voss, Maren, additional, and Rehder, Gregor, additional
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- 2023
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13. Long-term alkalinity trends in the Baltic Sea and their implications for CO₂-induced acidification
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Müller, Jens Daniel, Schneider, Bernd, and Rehder, Gregor
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- 2016
14. A regional pCO2 climatology of the Baltic Sea from in situ pCOL2 observations and a model-based extrapolation approach.
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Bittig, Henry C., Jacobs, Erik, Neumann, Thomas, and Rehder, Gregor
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CLIMATOLOGY ,EXTRAPOLATION ,OCEAN temperature ,CARBON dioxide ,ATMOSPHERE - Abstract
Ocean surface pCO2 estimates are of great interest for the calculation of air-sea CO2 fluxes, oceanic uptake of anthropogenic CO2, and eventually the Global Carbon Budget. They are accessible from direct observations, which are discrete in space and time and thus always sparse, or from biogeochemical models, which only approximate reality. Here, a combined method for the extrapolation of pCO2 observations is presented that uses (1) model-based patterns of variability from an EOF analysis of variability with (2) observational data to constrain EOF pattern amplitudes in (3) an ensemble approach, 5 which locally adjusts the spatial scale of the mapping to the density of the observations. Thus, data-constrained, gap- and discontinuity-free mapped fields including local error estimates are obtained without the need for or dependence on ancillary data (like, e.g., satellite sea surface temperature maps). This extrapolation approach is generic in that it can be applied to any oceanic or coastal region covered by a suitable model and observations. It is used here to establish a regional pCO2 climatology of the Baltic Sea, largely based on ICOS-DE SOOP Finnmaid surface pCO2 observations between Lübeck-Travemünde 10 (Germany) and Helsinki (Finland). The climatology can serve as improved input for atmosphere-ocean CO2 flux estimation in this coastal environment. [ABSTRACT FROM AUTHOR]
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- 2023
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15. Non-Redfieldian carbon model for the Baltic Sea (ERGOM version 1.2) – implementation and budget estimates
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Neumann, Thomas, primary, Radtke, Hagen, additional, Cahill, Bronwyn, additional, Schmidt, Martin, additional, and Rehder, Gregor, additional
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- 2022
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16. Erosion of carbonate-bearing sedimentary rocks may close the alkalinity budget of the Baltic Sea and support atmospheric CO2 uptake in coastal seas
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Wallmann, Klaus, primary, Diesing, Markus, additional, Scholz, Florian, additional, Rehder, Gregor, additional, Dale, Andrew W., additional, Fuhr, Michael, additional, and Suess, Erwin, additional
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- 2022
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17. Global Carbon Budget 2021
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Friedlingstein, Pierre, Jones, Matthew W., O'Sullivan, Michael, Andrew, Robbie M., Bakker, Dorothee C.E., Hauck, Judith, Le Quéré, Corinne, Peters, Glen P., Peters, Wouter, Pongratz, Julia, Sitch, Stephen, Canadell, Josep G., Ciais, Philippe, Jackson, Rob B., Alin, Simone R., Anthoni, Peter, Bates, Nicholas R., Becker, Meike, Bellouin, Nicolas, Bopp, Laurent, Chau, Thi Tuyet Trang, Chevallier, Frédéric, Chini, Louise P., Cronin, Margot, Currie, Kim I., Decharme, Bertrand, Djeutchouang, Laique M., Dou, Xinyu, Evans, Wiley, Feely, Richard A., Feng, Liang, Gasser, Thomas, Gilfillan, Dennis, Gkritzalis, Thanos, Grassi, Giacomo, Gregor, Luke, Gruber, Nicolas, Gürses, Özgür, Harris, Ian, Houghton, Richard A., Hurtt, George C., Iida, Yosuke, Ilyina, Tatiana, Luijkx, Ingrid T., Jain, Atul, Jones, Steve D., Kato, Etsushi, Kennedy, Daniel, Goldewijk, Kees Klein, Knauer, Jürgen, Korsbakken, Jan Ivar, Körtzinger, Arne, Landschützer, Peter, Lauvset, Siv K., Lefèvre, Nathalie, Lienert, Sebastian, Liu, Junjie, Marland, Gregg, McGuire, Patrick C., Melton, Joe R., Munro, David R., Nabel, Julia E.M.S., Nakaoka, Shin Ichiro, Niwa, Yosuke, Ono, Tsuneo, Pierrot, Denis, Poulter, Benjamin, Rehder, Gregor, Resplandy, Laure, Robertson, Eddy, Rödenbeck, Christian, Rosan, Thais M., Schwinger, Jörg, Schwingshackl, Clemens, Séférian, Roland, Sutton, Adrienne J., Sweeney, Colm, Tanhua, Toste, Tans, Pieter P., Tian, Hanqin, Tilbrook, Bronte, Tubiello, Francesco, Van Der Werf, Guido R., Vuichard, Nicolas, Wada, Chisato, Wanninkhof, Rik, Watson, Andrew J., Willis, David, Wiltshire, Andrew J., Yuan, Wenping, Yue, Chao, Yue, Xu, Zaehle, Sönke, Zeng, Jiye, Integr. Assessm. Global Environm. Change, and Environmental Sciences
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Earth and Planetary Sciences(all) - Abstract
Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize datasets and methodology to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the first time, an approach is shown to reconcile the difference in our ELUC estimate with the one from national greenhouse gas inventories, supporting the assessment of collective countries' climate progress. For the year 2020, EFOS declined by 5.4% relative to 2019, with fossil emissions at 9.5±0.5GtCyr-1 (9.3±0.5GtCyr-1 when the cement carbonation sink is included), and ELUC was 0.9±0.7GtCyr-1, for a total anthropogenic CO2 emission of 10.2±0.8GtCyr-1 (37.4±2.9GtCO2). Also, for 2020, GATM was 5.0±0.2GtCyr-1 (2.4±0.1ppmyr-1), SOCEAN was 3.0±0.4GtCyr-1, and SLAND was 2.9±1GtCyr-1, with a BIM of -0.8GtCyr-1. The global atmospheric CO2 concentration averaged over 2020 reached 412.45±0.1ppm. Preliminary data for 2021 suggest a rebound in EFOS relative to 2020 of +4.8% (4.2% to 5.4%) globally. Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959-2020, but discrepancies of up to 1GtCyr-1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use changes emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extra-tropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and datasets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this dataset (Friedlingstein et al., 2020, 2019; Le Quéré et al., 2018b, a, 2016, 2015b, a, 2014, 2013). The data presented in this work are available at 10.18160/gcp-2021 (Friedlingstein et al., 2021).
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- 2022
18. Global Carbon Budget 2021
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Friedlingstein, Pierre, primary, Jones, Matthew W., additional, O'Sullivan, Michael, additional, Andrew, Robbie M., additional, Bakker, Dorothee C. E., additional, Hauck, Judith, additional, Le Quéré, Corinne, additional, Peters, Glen P., additional, Peters, Wouter, additional, Pongratz, Julia, additional, Sitch, Stephen, additional, Canadell, Josep G., additional, Ciais, Philippe, additional, Jackson, Rob B., additional, Alin, Simone R., additional, Anthoni, Peter, additional, Bates, Nicholas R., additional, Becker, Meike, additional, Bellouin, Nicolas, additional, Bopp, Laurent, additional, Chau, Thi Tuyet Trang, additional, Chevallier, Frédéric, additional, Chini, Louise P., additional, Cronin, Margot, additional, Currie, Kim I., additional, Decharme, Bertrand, additional, Djeutchouang, Laique M., additional, Dou, Xinyu, additional, Evans, Wiley, additional, Feely, Richard A., additional, Feng, Liang, additional, Gasser, Thomas, additional, Gilfillan, Dennis, additional, Gkritzalis, Thanos, additional, Grassi, Giacomo, additional, Gregor, Luke, additional, Gruber, Nicolas, additional, Gürses, Özgür, additional, Harris, Ian, additional, Houghton, Richard A., additional, Hurtt, George C., additional, Iida, Yosuke, additional, Ilyina, Tatiana, additional, Luijkx, Ingrid T., additional, Jain, Atul, additional, Jones, Steve D., additional, Kato, Etsushi, additional, Kennedy, Daniel, additional, Klein Goldewijk, Kees, additional, Knauer, Jürgen, additional, Korsbakken, Jan Ivar, additional, Körtzinger, Arne, additional, Landschützer, Peter, additional, Lauvset, Siv K., additional, Lefèvre, Nathalie, additional, Lienert, Sebastian, additional, Liu, Junjie, additional, Marland, Gregg, additional, McGuire, Patrick C., additional, Melton, Joe R., additional, Munro, David R., additional, Nabel, Julia E. M. S., additional, Nakaoka, Shin-Ichiro, additional, Niwa, Yosuke, additional, Ono, Tsuneo, additional, Pierrot, Denis, additional, Poulter, Benjamin, additional, Rehder, Gregor, additional, Resplandy, Laure, additional, Robertson, Eddy, additional, Rödenbeck, Christian, additional, Rosan, Thais M., additional, Schwinger, Jörg, additional, Schwingshackl, Clemens, additional, Séférian, Roland, additional, Sutton, Adrienne J., additional, Sweeney, Colm, additional, Tanhua, Toste, additional, Tans, Pieter P., additional, Tian, Hanqin, additional, Tilbrook, Bronte, additional, Tubiello, Francesco, additional, van der Werf, Guido R., additional, Vuichard, Nicolas, additional, Wada, Chisato, additional, Wanninkhof, Rik, additional, Watson, Andrew J., additional, Willis, David, additional, Wiltshire, Andrew J., additional, Yuan, Wenping, additional, Yue, Chao, additional, Yue, Xu, additional, Zaehle, Sönke, additional, and Zeng, Jiye, additional
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- 2022
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19. Biogeochemical functioning of the Baltic Sea
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Kuliński, Karol, Rehder, Gregor, Asmala, Eero, Bartosova, Alena, Carstensen, Jacob, Gustafsson, Bo, Hall, Per O.J., Humborg, Christoph, Jilbert, Tom, Jürgens, Klaus, Meier, H. E.Markus, Müller-Karulis, Bärbel, Naumann, Michael, Olesen, Jørgen E., Savchuk, Oleg, Schramm, Andreas, Slomp, Caroline P., Sofiev, Mikhail, Sobek, Anna, Szymczycha, Beata, Undeman, Emma, Geochemistry, General geochemistry, Ilmatieteen laitos, Finnish Meteorological Institute, Department of Geosciences and Geography, Helsinki Institute of Sustainability Science (HELSUS), Environmental Geochemistry, Aquatic Biogeochemistry Research Unit (ABRU), Marine Ecosystems Research Group, Geochemistry, and General geochemistry
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1171 Geosciences ,Oceanography, Hydrology and Water Resources ,Baltic Sea ,General Earth and Planetary Sciences ,Earth and Planetary Sciences(all) ,biochemistry ,Oceanografi, hydrologi och vattenresurser ,ecology ,1172 Environmental sciences - Abstract
Location, specific topography, and hydrographic setting together with climate change and strong anthropogenic pressure are the main factors shaping the biogeochemical functioning and thus also the ecological status of the Baltic Sea. The recent decades have brought significant changes in the Baltic Sea. First, the rising nutrient loads from land in the second half of the 20th century led to eutrophication and spreading of hypoxic and anoxic areas, for which permanent stratification of the water column and limited ventilation of deep-water layers made favourable conditions. Since the 1980s the nutrient loads to the Baltic Sea have been continuously decreasing. This, however, has so far not resulted in significant improvements in oxygen availability in the deep regions, which has revealed a slow response time of the system to the reduction of the land-derived nutrient loads. Responsible for that is the low burial efficiency of phosphorus at anoxic conditions and its remobilization from sediments when conditions change from oxic to anoxic. This results in a stoichiometric excess of phosphorus available for organic-matter production, which promotes the growth of N2-fixing cyanobacteria and in turn supports eutrophication. This assessment reviews the available and published knowledge on the biogeochemical functioning of the Baltic Sea. In its content, the paper covers the aspects related to changes in carbon, nitrogen, and phosphorus (C, N, and P) external loads, their transformations in the coastal zone, changes in organic-matter production (eutrophication) and remineralization (oxygen availability), and the role of sediments in burial and turnover of C, N, and P. In addition to that, this paper focuses also on changes in the marine CO2 system, the structure and functioning of the microbial community, and the role of contaminants for biogeochemical processes. This comprehensive assessment allowed also for identifying knowledge gaps and future research needs in the field of marine biogeochemistry in the Baltic Sea.
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- 2022
20. 6. Wochenbericht MSM105
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Sabbaghzadeh, Bita, Rehder, Gregor, and Mohrholz, Volker
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FS MARIA S. MERIAN Fahrt MSM105 11.01.2022 – 23.02.2022 Walvis Bay – Mindelo BUSUC II Das Benguela-System im Klimawandel - Auswirkungen der Variabilität des physikalischen Antriebs auf den Kohlenstoff- und Sauerstoffhaushalt 6. Wochenbericht 14. - 20.02.2022
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- 2022
21. Non-Redfieldian carbon model for the Baltic Sea (ERGOM version 1.2) – implementation and budget estimates
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Neumann, Thomas, Radtke, Hagen, Cahill, Bronwyn, Schmidt, Martin, and Rehder, Gregor
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Marine biogeochemical models based on Redfield stoichiometry suffer from underestimating carbon fixation by primary production. The most pronounced indication of this is the overestimation of the dissolved inorganic carbon (DIC) concentration and, consequently, the partial pressure of carbon dioxide in surface waters. The reduced production of organic carbon will impact most biogeochemical processes. We propose a marine biogeochemical model allowing for a non-Redfieldian carbon fixation. The updated model is able to reproduce observed partial pressure of carbon dioxide and other variables of the ecosystem, like nutrients and oxygen, reasonably well. The additional carbon uptake is realized in the model by an extracellular release (ER) of dissolved organic matter (DOM) from phytoplankton. Dissolved organic matter is subject to flocculation and the sinking particles remove carbon from surface waters. This approach is mechanistically different from existing non-Redfieldian models which allow for flexible elemental ratios for the living cells of the phytoplankton itself. The performance of the model is demonstrated as an example for the Baltic Sea. We have chosen this approach because of a reduced computational effort which is beneficial for large-scale and long-term model simulations. Budget estimates for carbon illustrate that the Baltic Sea acts as a carbon sink. For alkalinity, the Baltic Sea is a source due to internal alkalinity generation by denitrification. Owing to the underestimated model alkalinity, an unknown alkalinity source or underestimated land-based fluxes still exist.
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- 2022
22. The diurnal cycle of <i>p</i>CO<sub>2</sub> in the coastal region of the Baltic Sea
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Honkanen, Martti, primary, Müller, Jens Daniel, additional, Seppälä, Jukka, additional, Rehder, Gregor, additional, Kielosto, Sami, additional, Ylöstalo, Pasi, additional, Mäkelä, Timo, additional, Hatakka, Juha, additional, and Laakso, Lauri, additional
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- 2021
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23. Cyanobacteria net community production in the Baltic Sea as inferred from profiling <i>p</i>CO<sub>2</sub> measurements
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Müller, Jens Daniel, primary, Schneider, Bernd, additional, Gräwe, Ulf, additional, Fietzek, Peer, additional, Wallin, Marcus Bo, additional, Rutgersson, Anna, additional, Wasmund, Norbert, additional, Krüger, Siegfried, additional, and Rehder, Gregor, additional
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- 2021
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24. Cyanobacteria net community production in the Baltic Sea as inferred from profiling pCO2 measurements
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Müller, Jens Daniel, Schneider, Bernd, Gräwe, Ulf, Fietzek, Peer, Wallin, Marcus Bo, Rutgersson, Anna, Wasmund, Norbert, Krüger, Siegfried, and Rehder, Gregor
- Abstract
Organic matter production by cyanobacteria blooms is a major environmental concern for the Baltic Sea as it promotes thespread of anoxic zones. Partial pressure of carbon dioxide (pCO2) measurements carried out on Ships of Opportunity (SOOP) since 2003 have proven to be a powerful tool to resolve the carbon dynamics of the blooms in space and time. However, SOOP measurements lack the possibility to directly constrain the depth–integrated net community production (NCP) due to their restriction to the sea surface. This study tackles the resulting knowledge gap through (1) providing a best–guess NCP estimatefor an individual cyanobacteria bloom based on repeated profiling measurements of pCO2 and (2) establishing an algorithm to accurately reconstruct depth–integrated NCP from surface pCO2 observations in combination with modelled temperature profiles. Goal (1) was achieved by deploying state–of–the–art sensor technology from a small–scale sailing vessel. The low–cost and flexible platform enabled observations covering an entire bloom event that occurred in July and August 2018 in the Eastern Gotland Sea. For the biogeochemical interpretation, recorded pCO2 profiles were converted to CT*, which is the dissolved inorganic carbon concentration normalised to alkalinity. We found that the investigated Nodularia–dominated bloom event had many biogeochemical characteristics in common with blooms in previous years. In particular, it lasted for about three weeks, caused a CT* drawdown of 80 μmol kg−1, and was accompanied by a sea surface temperature increase of 10 °C. The novel finding of this study is the vertical extension of the CT* drawdown up to 12 m water depth. Integration of the CT* drawdown across this depth and correction for vertical fluxes permit a best–guess NCP estimate of ~1.2 mol–C m−2. Addressing goal (2), we combined modelled hydrographical profiles with surface pCO2 observations recorded by SOOP Finnmaid within the study area. Introducing the temperature penetration depth (TPD) as a new parameter to integrate SOOP observations across depth, we achieve a reconstructed NCP estimate that agrees to the best–guess within 10 %. Applying the TPD approach to almost two decades of surface pCO2 observations available for the Baltic Sea bears the potential to provide new insights into the control and long–term trends of cyanobacteria NCP. This understanding is key for an effective design and monitoring of conservation measures aiming at a Good Environmental Status of the Baltic Sea.
- Published
- 2021
25. Technical note: Seamless gas measurements across the land–ocean aquatic continuum – corrections and evaluation of sensor data for CO2, CH4 and O2 from field deployments in contrasting environments
- Author
-
Canning, Anna Rose, Fietzek, Peer, Rehder, Gregor, and Körtzinger, Arne
- Abstract
The ocean and inland waters are two separate regimes, with concentrations in greenhouse gases differing on orders of magnitude between them. Together, they create the land–ocean aquatic continuum (LOAC), which comprises itself largely of areas with little to no data with regards to understanding the global carbon system. Reasons for this include remote and inaccessible sample locations, often tedious methods that require collection of water samples and subsequent analysis in the lab, and the complex interplay of biological, physical and chemical processes. This has led to large inconsistencies, increasing errors and has inevitably lead to potentially false upscaling. A set-up of multiple pre-existing oceanographic sensors allowing for highly detailed and accurate measurements was successfully deployed in oceanic to remote inland regions over extreme concentration ranges. The set-up consists of four sensors simultaneously measuring pCO2, pCH4 (both flow-through, membrane-based non-dispersive infrared (NDIR) or tunable diode laser absorption spectroscopy (TDLAS) sensors), O2 and a thermosalinograph at high resolution from the same water source. The flexibility of the system allowed for deployment from freshwater to open ocean conditions on varying vessel sizes, where we managed to capture day–night cycles, repeat transects and also delineate small-scale variability. Our work demonstrates the need for increased spatiotemporal monitoring and shows a way of homogenizing methods and data streams in the ocean and limnic realms.
- Published
- 2021
26. Technical note: Seamless gas measurements across Land-Ocean Aquatic Continuum – corrections and evaluation of sensor data for CO2, CH4 and O2 from field deployments in contrasting environments
- Author
-
Canning, Anna, Fietzek, Peer, Rehder, Gregor, and Körtzinger, Arne
- Abstract
The ocean and inland waters are two separate regimes, with concentrations in greenhouse gases differing on orders of magnitude between them. Together, they create the land–ocean aquatic continuum (LOAC), which comprises itself largely of areas with little to no data with regards to understanding the global carbon system. Reasons for this include remote and inaccessible sample locations, often tedious methods that require collection of water samples and subsequent analysis in the lab, and the complex interplay of biological, physical and chemical processes. This has led to large inconsistencies, increasing errors and has inevitably lead to potentially false upscaling. A set-up of multiple pre-existing oceanographic sensors allowing for highly detailed and accurate measurements was successfully deployed in oceanic to remote inland regions over extreme concentration ranges. The set-up consists of four sensors simultaneously measuring pCO2, pCH4 (both flow-through, membrane-based non-dispersive infrared (NDIR) or tunable diode laser absorption spectroscopy (TDLAS) sensors), O2 and a thermosalinograph at high resolution from the same water source. The flexibility of the system allowed for deployment from freshwater to open ocean conditions on varying vessel sizes, where we managed to capture day–night cycles, repeat transects and also delineate small-scale variability. Our work demonstrates the need for increased spatiotemporal monitoring and shows a way of homogenizing methods and data streams in the ocean and limnic realms.
- Published
- 2021
27. The northern European shelf as an increasing net sink for CO2
- Author
-
Becker, Meike, Olsen, Are, Landschützer, Peter, Omar, Abdirahman, Rehder, Gregor, Rödenbeck, Christian, and Skjelvan, Ingunn
- Subjects
TheoryofComputation_MATHEMATICALLOGICANDFORMALLANGUAGES - Abstract
We developed a simple method to refine existing open-ocean maps and extend them towards different coastal seas. Using a multi-linear regression we produced monthly maps of surface ocean fCO2 in the northern European coastal seas (the North Sea, the Baltic Sea, the Norwegian Coast and the Barents Sea) covering a time period from 1998 to 2016. A comparison with gridded Surface Ocean CO2 Atlas (SOCAT) v5 data revealed mean biases and standard deviations of 0 ± 26 µatm in the North Sea, 0 ± 16 µatm along the Norwegian Coast, 0 ± 19 µatm in the Barents Sea and 2 ± 42 µatm in the Baltic Sea. We used these maps to investigate trends in fCO2, pH and air–sea CO2 flux. The surface ocean fCO2 trends are smaller than the atmospheric trend in most of the studied regions. The only exception to this is the western part of the North Sea, where sea surface fCO2 increases by 2 µatm yr−1, which is similar to the atmospheric trend. The Baltic Sea does not show a significant trend. Here, the variability was much larger than the expected trends. Consistently, the pH trends were smaller than expected for an increase in fCO2 in pace with the rise of atmospheric CO2 levels. The calculated air–sea CO2 fluxes revealed that most regions were net sinks for CO2. Only the southern North Sea and the Baltic Sea emitted CO2 to the atmosphere. Especially in the northern regions the sink strength increased during the studied period.
- Published
- 2021
28. Cyanobacteria net community production in the Baltic Sea as inferred from profiling pCO2 measurements
- Author
-
Mueller, Jens Daniel, Schneider, Bernd, Graewe, Ulf, Fietzek, Peer, Wallin, Marcus, Rutgersson, Anna, Wasmund, Norbert, Krueger, Siegfried, and Rehder, Gregor
- Subjects
Oceanography, Hydrology and Water Resources ,Ecology ,Oceanografi, hydrologi och vattenresurser - Abstract
Organic matter production by cyanobacteria blooms is a major environmental concern for the Baltic Sea, as it promotes the spread of anoxic zones. Partial pressure of carbon dioxide (pCO2) measurements carried out on Ships of Opportunity (SOOP) since 2003 have proven to be a powerful tool to resolve the carbon dynamics of the blooms in space and time. However, SOOP measurements lack the possibility to directly constrain depth-integrated net community production (NCP) in moles of carbon per surface area due to their restriction to the sea surface. This study tackles the knowledge gap through (1) providing an NCP best guess for an individual cyanobacteria bloom based on repeated profiling measurements of pCO2 and (2) establishing an algorithm to accurately reconstruct depth-integrated NCP from surface pCO2 observations in combination with modelled temperature profiles. Goal (1) was achieved by deploying state-of-the-art sensor technology from a small-scale sailing vessel. The low-cost and flexible platform enabled observations covering an entire bloom event that occurred in July–August 2018 in the Eastern Gotland Sea. For the biogeochemical interpretation, recorded pCO2 profiles were converted to C∗T , which is the dissolved inorganic carbon concentration normalised to alkalinity. We found that the investigated bloom event was dominated by Nodularia and had many biogeochemical characteristics in common with blooms in previous years. In particular, it lasted for about 3 weeks, caused a C∗T drawdown of 90 µmol kg−1, and was accompanied by a sea surface temperature increase of 10 ∘C. The novel finding of this study is the vertical extension of the C∗T drawdown up to the compensation depth located at around 12 m. Integration of the C∗T drawdown across this depth and correction for vertical fluxes leads to an NCP best guess of ∼1.2 mol m−2 over the productive period. Addressing goal (2), we combined modelled hydrographical profiles with surface pCO2 observations recorded by SOOP Finnmaid within the study area. Introducing the temperature penetration depth (TPD) as a new parameter to integrate SOOP observations across depth, we achieve an NCP reconstruction that agrees to the best guess within 10 %, which is considerably better than the reconstruction based on a classical mixed-layer depth constraint. Applying the TPD approach to almost 2 decades of surface pCO2 observations available for the Baltic Sea bears the potential to provide new insights into the control and long-term trends of cyanobacteria NCP. This understanding is key for an effective design and monitoring of conservation measures aiming at a Good Environmental Status of the Baltic Sea., Biogeosciences, 18 (17), ISSN:1726-4170
- Published
- 2021
- Full Text
- View/download PDF
29. Air–sea CO2 exchange in the Baltic Sea—A sensitivity analysis of the gas transfer velocity
- Author
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Gutiérrez Loza, Lucia, Wallin, Marcus B., Sahlée, Erik, Holding, Thomas, Shutler, Jamie D., Rehder, Gregor, and Rutgersson, Anna
- Subjects
Baltic Sea ,Meteorology and Atmospheric Sciences ,CO2 exchange ,Meteorologi och atmosfärforskning ,Air–sea exchange ,Transfer velocity parametrization - Abstract
Air–sea gas fluxes are commonly estimated using wind-based parametrizations of the gas transfer velocity. However, neglecting gas exchange forcing mechanisms – other than wind speed – may lead to large uncertainties in the flux estimates and the carbon budgets, in particular, in heterogeneous environments such as marginal seas and coastal areas. In this study we investigated the impact of including relevant processes to the air–sea CO2 flux parametrization for the Baltic Sea. We used six parametrizations of the gas transfer velocity to evaluate the effect of precipitation, water-side convection, and surfactants on the net CO2 flux at regional and sub-regional scale. The differences both in the mean CO2 fluxes and the integrated net fluxes were small between the different cases. However, the implications on the seasonal variability were shown to be significant. The inter-annual and spatial variability were also found to be associated with the forcing mechanisms evaluated in the study. In addition to wind, water-side convection was the most relevant parameter controlling the air–sea gas exchange at seasonal and inter-annual scales. The effect of precipitation and surfactants seemed negligible in terms of the inter-annual variability. The effect of water-side convection and surfactants resulted in a reduction of the downward fluxes, while precipitation was the only parameter that resulted in an enhancement of the net uptake in the Baltic Sea.
- Published
- 2021
30. The diurnal cycle of pCO2 in the coastal region of the Baltic Sea
- Author
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Honkanen, Martti, Müller, Jens Daniel, Seppälä, Jukka, Rehder, Gregor, Kielosto, Sami, Ylöstalo, Pasi, Mäkelä, Timo, Hatakka, Juha, and Laakso, Lauri
- Subjects
respiratory system ,respiratory tract diseases ,circulatory and respiratory physiology - Abstract
The direction and magnitude of carbon dioxide fluxes between the atmosphere and the sea are regulated by the gradient in the partial pressure of carbon dioxide (pCO2) across the air–sea interface. Typically, observations of pCO2 at the sea surface are carried out by using research vessels and ships of opportunity, which usually do not resolve the diurnal cycle of pCO2 at a given location. This study evaluates the magnitude and driving processes of the diurnal cycle of pCO2 in a coastal region of the Baltic Sea. We present pCO2 data from July 2018 to June 2019 measured in the vicinity of the island of Utö at the outer edge of the Archipelago Sea, and quantify the relevant physical, biological, and chemical processes controlling pCO2. The highest monthly median of diurnal pCO2 variability (31 µatm) was observed in August and predominantly driven by biological processes. Biological fixation and mineralization of carbon led to sinusoidal diurnal pCO2 variations, with a maximum in the morning and a minimum in the afternoon. Compared with the biological carbon transformations, the impacts of air–sea fluxes and temperature changes on pCO2 were small, with their contributions to the monthly medians of diurnal pCO2 variability being up to 12 and 5 µatm, respectively. During upwelling events, short-term pCO2 variability (up to 500 µatm within a day) largely exceeded the usual diurnal cycle. If the net annual air–sea flux of carbon dioxide at our study site and for the sampled period is calculated based on a data subset that consists of only one regular measurement per day, the bias in the net exchange depends on the sampling time and can amount up to ±12 %. This finding highlights the importance of continuous surface pCO2 measurements at fixed locations for the assessment of the short-term variability of the carbonate system and the correct determination of air–sea CO2 fluxes., Ocean Science, 17 (6), ISSN:1812-0784, ISSN:1812-0792
- Published
- 2021
31. Science in brief: OMAI – Assessing acidification in the Baltic Sea : Monitoring and scientific basis
- Author
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Gustafsson, Erik, Gustafsson, Bo G., Carstensen, Jacob, Rehder, Gregor, and Fleming, Vivi
- Subjects
fungi ,Naturvetenskap ,population characteristics ,Natural Sciences ,humanities ,geographic locations - Abstract
Anthropogenic CO2 emissions will – unless reduced – move the Baltic Sea towards a state where acidification leads to changes in species composition, potentially influencing ecosystem functioning. Model simulations indicate that acidification in the Baltic Sea generally follows the same trajectory as the open oceans, with a pH decline of 0.6 units by year 2200 in the worst-case scenario. The Baltic Sea is highly influenced by its catchment areas, which means that acidification trends are generally more complex than in the open ocean. Improved coverage of acidification monitoring is necessary to broaden the understanding of current trends, improve the capacity to predict future changes, and as an added value provide insight into productivity patterns and eutrophication trends. An indicator for acidification in the Baltic Sea is currently under development.
- Published
- 2021
32. Upwelling-induced trace gas dynamics in the Baltic Sea inferred from 8 years of autonomous measurements on a ship of opportunity
- Author
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Jacobs, Erik, primary, Bittig, Henry C., additional, Gräwe, Ulf, additional, Graves, Carolyn A., additional, Glockzin, Michael, additional, Müller, Jens D., additional, Schneider, Bernd, additional, and Rehder, Gregor, additional
- Published
- 2021
- Full Text
- View/download PDF
33. Decoupling salinity and carbonate chemistry: low calcium ion concentration rather than salinity limits calcification in Baltic Sea mussels
- Author
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Sanders, Trystan, primary, Thomsen, Jörn, additional, Müller, Jens Daniel, additional, Rehder, Gregor, additional, and Melzner, Frank, additional
- Published
- 2021
- Full Text
- View/download PDF
34. Diurnal cycle of the CO2 system in the coastal region of the Baltic Sea
- Author
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Honkanen, Martti, Müller, Jens Daniel, Seppälä, Jukka, Rehder, Gregor, Kielosto, Sami, Ylöstalo, Pasi, Mäkelä, Timo, Hatakka, Juha, and Laakso, Lauri
- Abstract
The direction and magnitude of carbon dioxide exchange between the atmosphere and the sea is regulated by their difference in partial pressure of carbon dioxide (pCO2). Typically, observations of pCO2 are carried out by using research vessels and voluntary observing ships which cannot easily detect the diurnal cycle of pCO2 at a given location. This study evaluates the magnitude and driving processes of the diurnal cycle of pCO2 in a coastal region of the Baltic Sea during the different seasons.We present pCO2 data from July 2018–June 2019 carried out in the vicinity of the island of Utö in the Archipelago Sea and quantify the relevant physical, biological and chemical processes affecting pCO2. The highest monthly median diurnal pCO2 peak-to-peak amplitude (31 μatm) was observed in August. This high diurnal variation was found to be related predominantly to biological processes. The biological transformations of carbon generated a sinusoidal diurnal pCO2 variation, with a maximum in the morning and a minimum in the afternoon. Compared to the biological carbon transformations, the effect of air sea exchange of carbon dioxide and the effect of temperature changes on pCO2 are smaller, with their monthly median peak-to-peak amplitudes were up to 12 and 5 μatm, respectively. Single diurnal peak-to-peak amplitudes can be significantly larger (up to 500 μatm), during upwelling. If the net exchange of carbon dioxide between the sea and atmosphere on our study site and sampling period is calculated based on a data set that consists of only one measurement per day, the error in the budget depends on the sampling time and can be up to ±12 %.
- Published
- 2020
35. Dataset for Diurnal cycle of the CO2 system in the coastal region of the Baltic Sea (Submitted 2020/11)
- Author
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Honkanen, Martti, Müller, Jens Daniel, Seppälä, Jukka, Rehder, Gregor, Kielosto, Sami, Ylöstalo, Pasi, Mäkelä, Timo, Hatakka, Juha, and Laakso, Lauri
- Abstract
Dataset from Uto Atmospheric and Marine Research Station (59°46’55” N, 21°21’27” E) between July 2018 and June 2019 This is a dataset for the publication: Martti Honkanen, Jens Daniel Müller, Jukka Seppälä, Gregor Rehder, Sami Kielosto, Pasi Ylöstalo, Timo Mäkelä, Juha Hatakka, and Lauri Laakso: Diurnal cycle of the CO2 system in the coastal region of the Baltic Sea (Submitted to Ocean Science 2020/11). The dataset consists of 1 hour average values of the variables used in the paper. The data are in a comma separated file that has blanks as the nan values.
- Published
- 2020
- Full Text
- View/download PDF
36. Nutrient release and flux dynamics of CO2, CH4, and N2O in a coastal peatland driven by actively induced rewetting with brackish water from the Baltic Sea.
- Author
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Pönisch, Daniel Lars, Breznikar, Anne, Gutekunst, Cordula Nina, Jurasinski, Gerald, Rehder, Gregor, and Voss, Maren
- Subjects
BRACKISH waters ,EMISSIONS (Air pollution) ,CARBON emissions ,TERRITORIAL waters ,ELECTROPHILES ,GREENHOUSE gas mitigation - Abstract
The rewetting of drained peatlands supports long-term nutrient removal in addition to reducing emissions of carbon dioxide (CO
2 ) and nitrous oxide (N2 O). However, rewetting may lead to short-term nutrient leaching into adjacent water and high methane (CH4 ) emissions. The consequences of rewetting with brackish water on nutrient and greenhouse gas (GHG) fluxes remain unclear, although beneficial effects such as lower CH4 emissions seem likely. Therefore, we studied the actively induced rewetting of a coastal peatland with brackish water, by comparing pre- and post-rewetting data from the peatland and the adjacent bay. Both the potential transport of nutrients into adjacent coastal water and the shift of GHG fluxes (CO2 , CH4 , N2 O) accompanying the change from drained to inundated conditions were analyzed based on measurements of the surface water concentrations of nutrients (dissolved inorganic nitrogen (DIN), phosphate (PO4 3- )), oxygen (O2 ), components of the CO2 system, CH4 , and N2 O together with manual closed-chamber measurements of GHG fluxes. Our results revealed higher nutrient concentrations in the rewetted peatland than in the adjacent bay, indicating that nutrients leached out of the peat and were exported to the bay. A comparison of DIN concentrations of the bay with those of an unaffected reference station showed a significant increase after rewetting. The total nutrient export out of the peatland ranged between 12.5 and 36.5 t yr−1 for DIN-N and 0.2 ± 0.5 t yr−1 for PO4 -P. The peatland was also a source of GHG in the first year after rewetting. However, the spatial and temporal variability decreased and high CH4 emissions, as reported for freshwater rewetting, did not occur. CO2 fluxes decreased slightly from 0.29 ± 0.74 g m−2 h−1 (pre-rewetting) to 0.26 ± 0.29 g m−2 h−1 (post-rewetting). The availability of organic matter (OM) and dissolved nutrients were likely the most important drivers of continued CO2 production. Pre-rewetting CH4 fluxes ranged from 0.13 ± 1.01 mg m−2 h−1 (drained land site) to 11.4 ± 37.5 mg m−2 h−1 (ditch). After rewetting, CH4 fluxes on the formerly dry land increased by 1 order of magnitude (1.74 ± 7.59 mg m−2 h−1 ), whereas fluxes from the former ditch decreased to 8.5 ± 26.9 mg m−2 h−1 . These comparatively low CH4 fluxes can likely be attributed to the suppression of methanogenesis by the available O2 and sulfate, which serve as alternative electron acceptors. The post-rewetting N2 O flux was low, with an annual mean of 0.02 ± 0.07 mg m−2 h−1 . Our results suggest that rewetted coastal peatlands could account for high, currently unmonitored nutrient inputs into adjacent coastal water, at least on a short time scale such as a few years. However, rewetting with brackish water may decrease GHG emissions and might be favored over freshwater rewetting in order to reduce CH4 emissions. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
37. Technical note: Seamless gas measurements across the land–ocean aquatic continuum – corrections and evaluation of sensor data for CO<sub>2</sub>, CH<sub>4</sub> and O<sub>2</sub> from field deployments in contrasting environments
- Author
-
Canning, Anna Rose, primary, Fietzek, Peer, additional, Rehder, Gregor, additional, and Körtzinger, Arne, additional
- Published
- 2021
- Full Text
- View/download PDF
38. The northern European shelf as an increasing net sink for CO<sub>2</sub>
- Author
-
Becker, Meike, primary, Olsen, Are, additional, Landschützer, Peter, additional, Omar, Abdirhaman, additional, Rehder, Gregor, additional, Rödenbeck, Christian, additional, and Skjelvan, Ingunn, additional
- Published
- 2021
- Full Text
- View/download PDF
39. Effects of variable oxygen regimes on mitochondrial bioenergetics and reactive oxygen species production in a marine bivalve, Mya arenaria
- Author
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Ouillon, Natascha, primary, Sokolov, Eugene P., additional, Otto, Stefan, additional, Rehder, Gregor, additional, and Sokolova, Inna M., additional
- Published
- 2021
- Full Text
- View/download PDF
40. Technical note: Seamless gas measurements across Land-Ocean Aquatic Continuum – corrections and evaluation of sensor data for CO2, CH4 and O2 from field deployments in contrasting environments
- Author
-
Canning, Anna, Körtzinger, Arne, Fietzek, Peer, and Rehder, Gregor
- Abstract
Comparatively the ocean and inland waters are two separate worlds, with concentrations in greenhouse gases having orders of magnitude in difference between the two. Together they create the Land-Ocean Aquatic Continuum (LOAC), which comprises itself largely of areas with little to no data in regards to understanding the global carbon system. Reasons for this include remote and inaccessible sample locations, often tedious methods that require collection of water samples and subsequent analysis in the lab, as well as the complex interplay of biological, physical and chemical processes. This has led to large inconsistencies, increasing errors and inevitably leading to potentially false upscaling. Here we demonstrate successful deployment in oceanic to remote inland regions, over extreme concentration ranges with multiple pre-existing oceanographic sensors combined set-up, allowing for highly detailed and accurate measurements. The set-up consists of sensors measuring pCO2, pCH4 (both flow-through, membrane-based NDIR or TDLAS sensors), O2, and a thermosalinograph at high-resolution from the same water source simultaneously. The flexibility of the system allowed deployment from freshwater to open ocean conditions on varying vessel sizes, where we managed to capture day-night cycles, repeat transects and also delineate small scale variability. Our work demonstrates the need for increased spatiotemporal monitoring, and shows a way to homogenize methods and data streams in the ocean and limnic realms.
- Published
- 2020
41. The northern European shelf as increasing net sink for CO2
- Author
-
Becker, Meike, Olsen, Are, Landschützer, Peter, Omar, Abdirhaman, Rehder, Gregor, Rödenbeck, Christian, and Skjelvan, Ingunn
- Abstract
We developed a simple method to refine existing open ocean maps towards different coastal seas. Using a multi linear regression we produced monthly maps of surface ocean fCO2 in the northern European coastal seas (North Sea, Baltic Sea, Norwegian Coast and in the Barents Sea) covering a time period from 1998 to 2016. A comparison with gridded SOCAT v5 data revealed standard deviations of the residuals 0 ± 26 μatm in the North Sea, 0 ± 16 μatm along the Norwegian Coast, 0 ± 19 μatm in the Barents Sea, and 2 ± 42 μatm in the Baltic Sea.We used these maps as basis to investigate trends in fCO2, pH and air-sea CO2 flux. The surface ocean fCO2 trends are smaller than the atmospheric trend in most of the studied region. Only the western part of the North Sea is showing an increase in fCO2 close to 2 μatm yr−1, which is similar to the atmospheric trend. The Baltic Sea does not show a significant trend. Here, the variability was much larger than possibly observable trends. Consistently, the pH trends were smaller than expected for an increase of fCO2 in pace with the rise of atmospheric CO2 levels. The calculated air-sea CO2 fluxes revealed that most regions were net sinks for CO2. Only the southern North Sea and the Baltic Sea emitted CO2 to the atmosphere. Especially in the northern regions the sink strength increased during the studied period.
- Published
- 2020
42. The FluxEngine air–sea gas flux toolbox: simplified interface and extensions for in situ analyses and multiple sparingly soluble gases
- Author
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Holding, Thomas, primary, Ashton, Ian G., additional, Shutler, Jamie D., additional, Land, Peter E., additional, Nightingale, Philip D., additional, Rees, Andrew P., additional, Brown, Ian, additional, Piolle, Jean-Francois, additional, Kock, Annette, additional, Bange, Hermann W., additional, Woolf, David K., additional, Goddijn-Murphy, Lonneke, additional, Pereira, Ryan, additional, Paul, Frederic, additional, Girard-Ardhuin, Fanny, additional, Chapron, Bertrand, additional, Rehder, Gregor, additional, Ardhuin, Fabrice, additional, and Donlon, Craig J., additional
- Published
- 2019
- Full Text
- View/download PDF
43. Global Carbon Budget 2019
- Author
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Friedlingstein, Pierre, primary, Jones, Matthew W., additional, O'Sullivan, Michael, additional, Andrew, Robbie M., additional, Hauck, Judith, additional, Peters, Glen P., additional, Peters, Wouter, additional, Pongratz, Julia, additional, Sitch, Stephen, additional, Le Quéré, Corinne, additional, Bakker, Dorothee C. E., additional, Canadell, Josep G., additional, Ciais, Philippe, additional, Jackson, Robert B., additional, Anthoni, Peter, additional, Barbero, Leticia, additional, Bastos, Ana, additional, Bastrikov, Vladislav, additional, Becker, Meike, additional, Bopp, Laurent, additional, Buitenhuis, Erik, additional, Chandra, Naveen, additional, Chevallier, Frédéric, additional, Chini, Louise P., additional, Currie, Kim I., additional, Feely, Richard A., additional, Gehlen, Marion, additional, Gilfillan, Dennis, additional, Gkritzalis, Thanos, additional, Goll, Daniel S., additional, Gruber, Nicolas, additional, Gutekunst, Sören, additional, Harris, Ian, additional, Haverd, Vanessa, additional, Houghton, Richard A., additional, Hurtt, George, additional, Ilyina, Tatiana, additional, Jain, Atul K., additional, Joetzjer, Emilie, additional, Kaplan, Jed O., additional, Kato, Etsushi, additional, Klein Goldewijk, Kees, additional, Korsbakken, Jan Ivar, additional, Landschützer, Peter, additional, Lauvset, Siv K., additional, Lefèvre, Nathalie, additional, Lenton, Andrew, additional, Lienert, Sebastian, additional, Lombardozzi, Danica, additional, Marland, Gregg, additional, McGuire, Patrick C., additional, Melton, Joe R., additional, Metzl, Nicolas, additional, Munro, David R., additional, Nabel, Julia E. M. S., additional, Nakaoka, Shin-Ichiro, additional, Neill, Craig, additional, Omar, Abdirahman M., additional, Ono, Tsuneo, additional, Peregon, Anna, additional, Pierrot, Denis, additional, Poulter, Benjamin, additional, Rehder, Gregor, additional, Resplandy, Laure, additional, Robertson, Eddy, additional, Rödenbeck, Christian, additional, Séférian, Roland, additional, Schwinger, Jörg, additional, Smith, Naomi, additional, Tans, Pieter P., additional, Tian, Hanqin, additional, Tilbrook, Bronte, additional, Tubiello, Francesco N., additional, van der Werf, Guido R., additional, Wiltshire, Andrew J., additional, and Zaehle, Sönke, additional
- Published
- 2019
- Full Text
- View/download PDF
44. Constraining the Oceanic Uptake and Fluxes of Greenhouse Gases by Building an Ocean Network of Certified Stations: The Ocean Component of the Integrated Carbon Observation System, ICOS-Oceans
- Author
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Steinhoff, Tobias, Gkritzalis, Thanos, Lauvset, Siv K., Jones, Stephen D., Schuster, Ute, Olsen, Are, Becker, Meike, Bozzano, Roberto, Brunetti, Fabio, Cantoni, Carolina, Cardin, Vanessa, Diverrès, Denis, Fiedler, Björn, Fransson, Agneta, Giani, Michele, Hartman, Sue, Hoppema, Mario, Jeansson, Emil, Johannessen, Truls, Kitidis, Vassilis, Körtzinger, Arne, Landa, Camilla S., Lefèvre, Nathalie, Luchetta, Anna, Naudts, Lieven, Nightingale, Philip, Omar, Abdirahman M., Pensieri, Sara, Pfeil, Benjamin, Castaño-Primo, Rocío, Rehder, Gregor, Rutgersson, Anna, Sanders, Richard, Schewe, Ingo, Siena, Giuseppe, Skjelvan, Ingunn, Soltwedel, Thomas, Van Heuven, Steven M. A. C., Watson, Andrew J., Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Flanders Marine Institute, VLIZ, Bjerknes Centre for Climate Research (BCCR), Department of Biological Sciences [Bergen] (BIO / UiB), University of Bergen (UiB)-University of Bergen (UiB), College of Life and Environmental Sciences [Exeter], University of Exeter, University of Leeds, Instrumentation, Moyens analytiques, Observatoires en Géophysique et Océanographie (IMAGO), Norwegian Polar Institute, Istituto Nazionale di Geofisica e di Oceanografia Sperimentale (OGS), Meteorological Research Institute [Tsukuba] (MRI), Japan Meteorological Agency (JMA), Plymouth Marine Laboratory (PML), Austral, Boréal et Carbone (ABC), 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), Royal Belgian Institute of Natural Sciences (RBINS), University of Bergen (UiB), Department of Earth Sciences [Uppsala], Uppsala University, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Centre for Isotope Research [Groningen] (CIO), University of Groningen [Groningen], European Project: 654410,H2020,H2020-INFRAIA-2014-2015,JERICO-NEXT(2015), Plymouth Marine Laboratory, 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), GEOMAR - Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), University of Bergen (UIB), 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)-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), Department of Earth Sciences [ Uppsala], and NASA Ames Research Center (ARC)
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[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] ,autonomous surface vehicle ,Climate Research ,ATC ,dissolved inorganic ,carbon portal ,ocean observation ,network design ,Oceanografi, hydrologi och vattenresurser ,flux maps ,Klimatforskning ,Oceanography, Hydrology and Water Resources ,CO2 fluxes ,Atmospheric Thematic Centre ,DIC ,CP ,carbon sink ,ComputingMilieux_MISCELLANEOUS ,ASV - Abstract
The European Research Infrastructure Consortium “Integrated Carbon Observation System” (ICOS) aims at delivering high quality greenhouse gas (GHG) observations and derived data products (e.g., regional GHG-flux maps) for constraining the GHG balance on a European level, on a sustained long-term basis. The marine domain (ICOS-Oceans) currently consists of 11 Ship of Opportunity lines (SOOP – Ship of Opportunity Program) and 10 Fixed Ocean Stations (FOSs) spread across European waters, including the North Atlantic and Arctic Oceans and the Barents, North, Baltic, and Mediterranean Seas. The stations operate in a harmonized and standardized way based on community-proven protocols and methods for ocean GHG observations, improving operational conformity as well as quality control and assurance of the data. This enables the network to focus on long term research into the marine carbon cycle and the anthropogenic carbon sink, while preparing the network to include other GHG fluxes. ICOS data are processed on a near real-time basis and will be published on the ICOS Carbon Portal (CP), allowing monthly estimates of CO2 air-sea exchange to be quantified for European waters. ICOS establishes transparent operational data management routines following the FAIR (Findable, Accessible, Interoperable, and Reusable) guiding principles allowing amongst others reproducibility, interoperability, and traceability. The ICOS-Oceans network is actively integrating with the atmospheric (e.g., improved atmospheric measurements onboard SOOP lines) and ecosystem (e.g., oceanic direct gas flux measurements) domains of ICOS, and utilizes techniques developed by the ICOS Central Facilities and the CP. There is a strong interaction with the international ocean carbon cycle community to enhance interoperability and harmonize data flow. The future vision of ICOS-Oceans includes ship-based ocean survey sections to obtain a three-dimensional understanding of marine carbon cycle processes and optimize the existing network design. publishedVersion
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- 2019
45. The Baltic TRANSCOAST approach – investigating shallow coasts as terrestrial-marine interface of water and matter fluxes
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Burchardt, Hans, Brede, Martin, Schulz-Vogt, Heide, Voss, Maren, Janssen, Manon, Sokolova, Inna, Böttcher, Michael, Schubert, Hendrik, Jurasinski, Gerald, Forster, Stefan, Rehder, Gregor, Karsten, Ulf, Leinweber, Peter, and Lennartz, Bernd
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bepress|Physical Sciences and Mathematics ,EarthArXiv|Physical Sciences and Mathematics|Oceanography and Atmospheric Sciences and Meteorology ,EarthArXiv|Life Sciences|Plant Sciences|Other Plant Sciences ,EarthArXiv|Physical Sciences and Mathematics|Environmental Sciences ,bepress|Physical Sciences and Mathematics|Earth Sciences ,EarthArXiv|Physical Sciences and Mathematics|Earth Sciences ,bepress|Life Sciences|Marine Biology ,EarthArXiv|Physical Sciences and Mathematics|Earth Sciences|Soil Science ,bepress|Life Sciences ,EarthArXiv|Physical Sciences and Mathematics|Oceanography and Atmospheric Sciences and Meteorology|Other Oceanography and Atmospheric Sciences and Meteorology ,bepress|Physical Sciences and Mathematics|Oceanography and Atmospheric Sciences and Meteorology ,EarthArXiv|Life Sciences ,EarthArXiv|Life Sciences|Biology ,bepress|Physical Sciences and Mathematics|Earth Sciences|Hydrology ,bepress|Physical Sciences and Mathematics|Environmental Sciences ,bepress|Life Sciences|Plant Sciences|Other Plant Sciences ,EarthArXiv|Physical Sciences and Mathematics|Environmental Sciences|Environmental Monitoring ,bepress|Life Sciences|Biology ,bepress|Physical Sciences and Mathematics|Oceanography and Atmospheric Sciences and Meteorology|Other Oceanography and Atmospheric Sciences and Meteorology ,EarthArXiv|Life Sciences|Marine Biology ,bepress|Physical Sciences and Mathematics|Environmental Sciences|Environmental Monitoring ,EarthArXiv|Physical Sciences and Mathematics ,bepress|Physical Sciences and Mathematics|Earth Sciences|Soil Science ,EarthArXiv|Life Sciences|Plant Sciences ,EarthArXiv|Physical Sciences and Mathematics|Earth Sciences|Biogeochemistry ,bepress|Life Sciences|Plant Sciences ,bepress|Physical Sciences and Mathematics|Earth Sciences|Biogeochemistry ,EarthArXiv|Physical Sciences and Mathematics|Earth Sciences|Hydrology - Abstract
In Baltic TRANSCOAST we study the physical, biogeochemical, and biological processes at the land-ocean interface. The coastal zone is heavily impacted by various human activities as well as by geomorphological and climatic processes – on both the land and the sea side. Land-sea interactions at low lying coastal areas that are often dominated by peatlands, and are a common feature along the Baltic Sea coast, are not well understood. The core hypothesis of Baltic TRANSCOAST is that the shallow sea and the terrestrial peatland have a mutual impact on each other with far-reaching consequences for water and energy fluxes, matter cycling and the biota. The interdisciplinary research focuses on the significance of flooding frequency and duration on biogeochemical processes by concentrating the investigations on three comparison sites. We are assessing how changing boundary conditions (such as climate and land use) affect the hydrology, biota and biogeochemical processes in coastal wetlands and the adjacent marine ecosystem.
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- 2019
46. A harmonized nitrous oxide (N2O) ocean observation network for the 21st century
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Bange, Hermann W., Arévalo-Martínez, Damian L., de la Paz, Mercedes, Farías, Laura, Kaiser, Jan, Kock, Annette, Law, Cliff S., Rees, Andrew P., Rehder, Gregor, Tortell, Philippe D., Upstill-Goddard, Robert C., and Wilson, Samuel T.
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Global and Planetary Change ,Ocean Engineering ,Aquatic Science ,Oceanography ,Water Science and Technology - Abstract
Nitrous oxide (N2O) is an important atmospheric trace gas involved in tropospheric warming and stratospheric ozone depletion. Estimates of the global ocean contribution to N2O emissions average 21% (range: 10 to 53%). Ongoing environmental changes such as warming, deoxygenation and acidification are affecting oceanic N2O cycling and emissions to the atmosphere. International activities over the last decades aimed at improving estimates of global N2O emissions, including (i) the MarinE MethanE and NiTrous Oxide database (MEMENTO) for archiving of quality-controlled data, and (ii) a recent large-scale inter-laboratory comparison by Working Group 143 of the Scientific Committee on Ocean Research (SCOR). To reduce uncertainties in oceanic N2O emission estimates and to characterize the spatial and temporal variability in N2O distributions in a changing ocean, we propose the establishment of a harmonized N2O Observation Network (N2O-ON) combining discrete and continuous data from various platforms. The network will integrate observations obtained by calibrated techniques, using time series measurements at fixed stations and repeated hydrographic sections on voluntary observing ships and research vessels. In addition to exploiting existing oceanographic infrastructure, we propose the establishment of central calibration facilities in selected international laboratories to improve accuracy, and ensure standardization and comparability of N2O measurements. Final data products will include a harmonized global N2O concentration and emission fields for use in model validation and projections of future oceanic N2O emissions, to inform the global research community and policy makers.
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- 2019
47. Global carbon budget 2019
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Friedlingstein, Pierre, Jones, Matthew W., O'Sullivan, Michael, Andrew, Robbie, Hauck, Judith, Peters, Glen Philip, Peters, Wouter, Pongratz, Julia, Sitch, Stephen, Le Quéré, Corinne, Bakker, Dorothée C.E., Canadell, Josep G., Ciais, Philippe, Jackson, Robert B., Anthoni, Peter, Barbero, Leticia, Bastos, Ana, Bastrikov, Vladislav, Becker, Meike, Bopp, Laurent, Buitenhuis, Erik, Chandra, Naveen, Chevallier, Frédéric, Chini, Louise P., Currie, Kim I., Feely, Richard A., Gehlen, Marion, Gilfillan, Dennis, Gkritzalis, Thanos, Goll, Daniel S., Gruber, Nicolas, Gutekunst, Sören, Harris, Ian, Haverd, Vanessa, Houghton, Richard A., Hurtt, George, Ilyina, Tatiana, Jain, Atul K., Joetzjer, Emilie, Kaplan, Jed O., Kato, Etsushi, Goldewijk, Kees Klein, Korsbakken, Jan Ivar, Landschutzer, Peter, Lauvset, Siv Kari, Lefevre, Nathalie, Lenton, Andrew, Lienert, Sebastian, Lombardozzi, Danica, Marland, Gregg, McGuire, Patrick C., Melton, Joe R., Metzl, Nicolas, Munro, David R., Nabel, Julia E.M.S., Nakaoka, Shin-Ichiro, Neill, Craig, Omar, Abdirahman, Ono, Tsuneo, Peregon, Anna, Pierrot, Denis, Poulter, Benjamin, Rehder, Gregor, Resplandy, Laure, Robertson, Eddy, Rödenbeck, Christian, Séférian, Roland, Schwinger, Jörg, Smith, Naomi, Tans, Pieter P., Tian, Hanqin, Tilbrook, Bronte, Tubiello, Francesco N., van der Werf, Guido R., Wiltshire, Andrew J., and Zaehle, Sönke
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Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere – the “global carbon budget” – is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFF) are based on energy statistics and cement production data, while emissions from land use change (ELUC), mainly deforestation, are based on land use and land use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) and terrestrial CO2 sink (SLAND) are estimated with global process models constrained by observations. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the last decade available (2009–2018), EFF was 9.5±0.5 GtC yr−1, ELUC 1.5±0.7 GtC yr−1, GATM 4.9±0.02 GtC yr−1 (2.3±0.01 ppm yr−1), SOCEAN 2.5±0.6 GtC yr−1, and SLAND 3.2±0.6 GtC yr−1, with a budget imbalance BIM of 0.4 GtC yr−1 indicating overestimated emissions and/or underestimated sinks. For the year 2018 alone, the growth in EFF was about 2.1 % and fossil emissions increased to 10.0±0.5 GtC yr−1, reaching 10 GtC yr−1 for the first time in history, ELUC was 1.5±0.7 GtC yr−1, for total anthropogenic CO2 emissions of 11.5±0.9 GtC yr−1 (42.5±3.3 GtCO2). Also for 2018, GATM was 5.1±0.2 GtC yr−1 (2.4±0.1 ppm yr−1), SOCEAN was 2.6±0.6 GtC yr−1, and SLAND was 3.5±0.7 GtC yr−1, with a BIM of 0.3 GtC. The global atmospheric CO2 concentration reached 407.38±0.1 ppm averaged over 2018. For 2019, preliminary data for the first 6–10 months indicate a reduced growth in EFF of +0.6 % (range of −0.2 % to 1.5 %) based on national emissions projections for China, the USA, the EU, and India and projections of gross domestic product corrected for recent changes in the carbon intensity of the economy for the rest of the world. Overall, the mean and trend in the five components of the global carbon budget are consistently estimated over the period 1959–2018, but discrepancies of up to 1 GtC yr−1 persist for the representation of semi-decadal variability in CO2 fluxes. A detailed comparison among individual estimates and the introduction of a broad range of observations shows (1) no consensus in the mean and trend in land use change emissions over the last decade, (2) a persistent low agreement between the different methods on the magnitude of the land CO2 flux in the northern extra-tropics, and (3) an apparent underestimation of the CO2 variability by ocean models outside the tropics. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this data set (Le Quéré et al., 2018a, b, 2016, 2015a, b, 2014, 2013). The data generated by this work are available at https://doi.org/10.18160/gcp-2019 (Friedlingstein et al., 2019).
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- 2019
48. Cyanobacteria net community production in the Baltic Sea as inferred from profiling pCO2 measurements.
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Müller, Jens Daniel, Schneider, Bernd, Gräwe, Ulf, Fietzek, Peer, Wallin, Marcus Bo, Rutgersson, Anna, Wasmund, Norbert, Krüger, Siegfried, and Rehder, Gregor
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OCEAN temperature ,ANOXIC zones ,SAILING ships ,CYANOBACTERIA ,PARTIAL pressure ,CYANOBACTERIAL blooms ,ALGAL blooms - Abstract
Organic matter production by cyanobacteria blooms is a major environmental concern for the Baltic Sea, as it promotes the spread of anoxic zones. Partial pressure of carbon dioxide (p CO2) measurements carried out on Ships of Opportunity (SOOP) since 2003 have proven to be a powerful tool to resolve the carbon dynamics of the blooms in space and time. However, SOOP measurements lack the possibility to directly constrain depth-integrated net community production (NCP) in moles of carbon per surface area due to their restriction to the sea surface. This study tackles the knowledge gap through (1) providing an NCP best guess for an individual cyanobacteria bloom based on repeated profiling measurements of p CO2 and (2) establishing an algorithm to accurately reconstruct depth-integrated NCP from surface p CO2 observations in combination with modelled temperature profiles. Goal (1) was achieved by deploying state-of-the-art sensor technology from a small-scale sailing vessel. The low-cost and flexible platform enabled observations covering an entire bloom event that occurred in July–August 2018 in the Eastern Gotland Sea. For the biogeochemical interpretation, recorded p CO2 profiles were converted to CT* , which is the dissolved inorganic carbon concentration normalised to alkalinity. We found that the investigated bloom event was dominated by Nodularia and had many biogeochemical characteristics in common with blooms in previous years. In particular, it lasted for about 3 weeks, caused a CT* drawdown of 90 µmolkg-1 , and was accompanied by a sea surface temperature increase of 10 ∘C. The novel finding of this study is the vertical extension of the CT* drawdown up to the compensation depth located at around 12 m. Integration of the CT* drawdown across this depth and correction for vertical fluxes leads to an NCP best guess of ∼1.2 molm-2 over the productive period. Addressing goal (2), we combined modelled hydrographical profiles with surface p CO2 observations recorded by SOOP Finnmaid within the study area. Introducing the temperature penetration depth (TPD) as a new parameter to integrate SOOP observations across depth, we achieve an NCP reconstruction that agrees to the best guess within 10 % , which is considerably better than the reconstruction based on a classical mixed-layer depth constraint. Applying the TPD approach to almost 2 decades of surface p CO2 observations available for the Baltic Sea bears the potential to provide new insights into the control and long-term trends of cyanobacteria NCP. This understanding is key for an effective design and monitoring of conservation measures aiming at a Good Environmental Status of the Baltic Sea. [ABSTRACT FROM AUTHOR]
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- 2021
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49. Baltic Earth Assessment Report on the biogeochemistry of the Baltic Sea.
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Kuliński, Karol, Rehder, Gregor, Asmala, Eero, Bartosova, Alena, Carstensen, Jacob, Gustafsson, Bo, Hall, Per O. J., Humborg, Christoph, Jilbert, Tom, Jürgens, Klaus, Meier, Markus, Müller-Karulis, Bärbel, Naumann, Michael, Olesen, Jørgen E., Savchuk, Oleg, Schramm, Andreas, Slomp, Caroline P., Sofiev, Mikhail, Sobek, Anna, and Szymczycha, Beata
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COASTAL sediments , *BIOGEOCHEMISTRY , *EFFECT of human beings on climate change , *ORGANIC compounds , *COASTS , *KNOWLEDGE gap theory - Abstract
Location, specific topography and hydrographic setting together with climate change and strong anthropogenic pressure are the main factors shaping the biogeochemical functioning and thus also the ecological status of the Baltic Sea. The recent decades have brought significant changes in the Baltic Sea. First, the rising nutrient loads from land in the second half of the 20th century led to eutrophication and spreading of hypoxic and anoxic areas, for which permanent stratification of the water column and limited ventilation of deep water layers made favourable conditions. Since the 1980s the nutrient loads to the Baltic Sea have been continuously decreasing. This, however, has so far not resulted in significant improvements in oxygen availability in the deep regions, which has revealed a slow response time of the system to the reduction of the land-derived nutrient loads. Responsible for that is the low burial efficiency of phosphorus at anoxic conditions and its remobilization from sediments when conditions change from oxic to anoxic. This results in a stoichiometric excess of phosphorus available for organic matter production, which promotes the growth of N2-fixing cyanobacteria and in turn supports eutrophication. This assessment reviews the available and published knowledge on the biogeochemical functioning of the Baltic Sea. In its content, the paper covers the aspects related to changes in carbon, nitrogen and phosphorus (C, N and P) external loads, their transformations in the coastal zone, changes in organic matter production (eutrophication) and remineralization (oxygen availability), and the role of sediments in burial and turnover of C, N and P. In addition to that, this paper focuses also on changes in the marine CO2 system, structure and functioning of the microbial community and the role of contaminants for biogeochemical processes. This comprehensive assessment allowed also for identifying knowledge gaps and future research needs in the field of marine biogeochemistry in the Baltic Sea. [ABSTRACT FROM AUTHOR]
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- 2021
- Full Text
- View/download PDF
50. Atmospheric GHG measurements onboard Voluntary Observing Ships - approaches for improved atmospheric sampling
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Steinhoff, Tobias, Delmotte, Marc, Hazan, Lynn, Jordan, Armin, Lavric, Jost, Lett, C., Lefevre, Nathalie, Ramonet, Michele, Rödenbeck, Christian, Rzesanke, Daniel, and Rehder, Gregor
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Autonomous systems measuring the partial pressure of CO2 (pCO2) in surface waters on commercial carrier ships (Voluntary Observing Ship, VOS), which allows for high spatiotemporal data coverage, are a major component of the Ocean Thematic Centre (OTC) data stream. Currently, ICOS operates lines in the Atlantic, North Sea and the Baltic. All lines are determining pCO2 by measuring CO2 in air that has been equilibrated with seawater. As part of the European H2020 project RINGO (https://www.icos-ri.eu/ringo), we are evaluating the possibility of using VOS to expand the atmospheric network. We will provide technical solutions for three different settings and approaches, and assess the added value for the atmospheric observation network. Two systems are designed as stand-alone modules for continuous atmospheric CO2 and CH4 measurements, following the technological requirements defined by the ATC, and will be operated in the Baltic (high anthropogenic influence) and on a line between France and Brazil (clean marine air, large temperature and humidity gradient). A second approach is using the existing instrumentation for seawater measurements (North Atlantic), which we aim to improve in order to make these measurements usable for the atmospheric research community. This is an effort that connects the ocean research community with the Central Analytical Laboratories (CAL; testing an extended range of standard gases, providing flask sampling opportunity), the Atmospheric Thematic Centre (ATC; work on data streams that can be digested by the ATC system), and the modelling community (identifying useful sampling strategies). Here we present a status update of the ongoing work, which is a joined effort of the atmospheric and ocean community within ICOS and relying on the expertise of both fields.
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- 2018
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