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1. Southern hemisphere circulation anomalies and impacts over subtropical South America due to different El Niño flavours

Author

Teresa Losada, Marcelo Barreiro, Verónica Martín-Gómez, and Belén Rodríguez-Fonseca

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, Advection, Física atmosférica, 0207 environmental engineering, 02 engineering and technology, Subtropics, Vorticity, 01 natural sciences, El Niño, Climatology, General Circulation Model, Environmental science, Precipitation, 020701 environmental engineering, Southern Hemisphere, 0105 earth and related environmental sciences, Teleconnection
Abstract

ENSO exhibits different flavors with worldwide impacts. However, the associated teleconnections with subtropical South America (SSA) are still controversial and modelling studies are needed. Here, we analyze the Southern Hemisphere (SH) circulation anomalies and the impacts over SSA during the austral summer due to different El Niño patterns (Canonical and El Niño Modoki). The analysis is performed considering reanalysis data and two different Atmospheric General Circulation Models (SPEEDY and UCLA - AGCM). Results from reanalysis show that positive precipitation anomalies develop over SSA during Canonical El Niño events. These anomalies are induced through an increase of upper level cyclonic vorticity advection and a stronger low-level southward moisture transport. However, in El Niño Modoki events, rainfall anomalies are observed over SSA only for the strongest events. Both models are able to reproduce the precipitation signal over SSA in the Canonical El Niño case, although the underlying physical mechanism depends on the model. In SPEEDY, the increased rainfall is due to an increase of the moisture transport toward SSA, while in UCLA - AGCM it is related to both, an increase of the low-level moisture transport toward SSA and the increase of upper level cyclonic vorticity advection. The precipitation signal associated with El Niño Modoki is more controversial. While UCLA - AGCM suggests a rainfall increase over SSA, SPEEDY, in agreement with observations, does not show any statistically significant signal. However, the upper level circulation anomalies reproduced by UCLA – AGCM are more consistent with reanalysis than those from SPEEDY, which makes UCLA – AGCM to be more reliable. This result suggests increased rainfall over SSA during El Niño Modoki.

Published
2020
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2. Relationships among Intermodel Spread and Biases in Tropical Atlantic Sea Surface Temperatures

Author

Teresa Losada, Elsa Mohino, Irene Polo, C. Roberto Mechoso, and Belén Rodríguez-Fonseca

Subjects
Systematic error, Atmospheric Science, 010504 meteorology & atmospheric sciences, General Circulation Model, Climatology, Environmental science, Climate model, Tropical Atlantic, 010502 geochemistry & geophysics, 01 natural sciences, 0105 earth and related environmental sciences
Abstract

State-of-the-art general circulation models show important systematic errors in their simulation of sea surface temperatures (SST), especially in the tropical Atlantic. In this work the spread in the simulation of climatological SST in the tropical Atlantic by 24 CMIP5 models is examined, and its relationship with the mean systematic biases in the region is explored. The modes of intermodel variability are estimated by applying principal component (PC) analysis to the SSTs in the region 70°W–20°E, 20°S–20°N. The intermodel variability is approximately explained by the first three modes. The first mode is related to warmer SSTs in the basin, shows worldwide connections with same-signed loads over most of the tropics, and is connected with lower low cloud cover over the eastern parts of the subtropical oceans. The second mode is restricted to the Atlantic, where it shows negative and positive loads to the north and south of the equator, respectively, and is connected to a too weak Atlantic meridional overturning circulation (AMOC). The third mode is related to the double intertropical convergence zone bias in the Pacific and to an interhemispheric asymmetry in the net radiation at the top of the atmosphere. The structure of the second mode is closer to the mean bias than that of the others in the tropical Atlantic, suggesting that model difficulties with the AMOC contribute to the regional biases.

Published
2019
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3. Skillful prediction of tropical Pacific fisheries provided by Atlantic Niños

Author

Elsa Mohino, Teresa Losada, Marta Coll, Irene Polo, Belén Rodríguez-Fonseca, Iñigo Gómara, European Commission, Universidad Complutense de Madrid, Ministerio de Ciencia, Innovación y Universidades (España), and Agencia Estatal de Investigación (España)

Subjects
El Niño-Southern Oscillation, Atlantic Niños, 010504 meteorology & atmospheric sciences, media_common.quotation_subject, Fishing, 0207 environmental engineering, Fisheries, Pantropical, 02 engineering and technology, 010501 environmental sciences, 01 natural sciences, Scarcity, Pantropical Interactions, Prediction model, Marine ecosystem, Ecosystem, 14. Life underwater, Predictability, 020701 environmental engineering, 0105 earth and related environmental sciences, General Environmental Science, media_common, Upwelling, Renewable Energy, Sustainability and the Environment, Public Health, Environmental and Occupational Health, Física atmosférica, Food web, Fishery, 13. Climate action, Environmental science
Abstract

12 pages, 4 figures.-- Data availability Annual catch data from FAO major fishing areas are available from the Sea Around Us Project (http://www.seaaroundus.org/data/#/fao). Hadley Centre Sea Ice and Sea Surface Temperature data set (HadISST) are available from the Met Office Hadley Centre observations datasets (https://www.metoffice.gov.uk/hadobs/hadisst/). National Centers for Environmental Prediction (NCEP) reanalysis data are available from the NOAA/OAR/ESRL PSL website (https://psl.noaa.gov/). GFDL COBALT and FishMIP simulation data (EcoOcean, BOATS and Macroecological) are accessible through the Potsdam-Institute for Climate Impact Research Earth System Grid Federation (ESGF) data node (https://esg.pik-potsdam.de/search/isimip/). Code availabilityS4CAST originally published MATLAB® code is open access and available from the Zenodo repository (doi:10.5281/zenodo.15985) in the URL https://zenodo.org/record/15985. The rest of MATLAB scripts used in this analysis can be made available upon request from the corresponding author (i.gomara@ucm.es). Updated S4CAST versions can be requested to the TROPA-UCM research group (brfonsec@ucm.es), Tropical Pacific upwelling-dependent ecosystems are the most productive and variable worldwide, mainly due to the influence of El Niño Southern Oscillation (ENSO). ENSO can be forecasted seasons ahead thanks to assorted climate precursors (local-Pacific processes, pantropical interactions). However, owing to observational data scarcity and bias-related issues in earth system models, little is known about the importance of these precursors for marine ecosystem prediction. With recently released reanalysis-nudged global marine ecosystem simulations, these constraints can be sidestepped, allowing full examination of tropical Pacific ecosystem predictability. By complementing historical fishing records with marine ecosystem model data, we show herein that equatorial Atlantic Sea Surface Temperatures (SSTs) constitute a superlative predictability source for tropical Pacific marine yields, which can be forecasted over large-scale areas up to 2 years in advance. A detailed physical-biological mechanism is proposed whereby Atlantic SSTs modulate upwelling of nutrient-rich waters in the tropical Pacific, leading to a bottom-up propagation of the climate-related signal across the marine food web. Our results represent historical and near-future climate conditions and provide a useful springboard for implementing a marine ecosystem prediction system in the tropical Pacific, This research was funded by the EU H2020 project TRIATLAS (no. 817578), the Universidad Complutense de Madrid project FEI-EU-19-09 and the Spanish Ministry of Economy and Competitiveness project PRE4CAST (CGL2017-86415-R)., With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

Published
2021

4. Tropical Atlantic Mixed Layer Buoyancy Seasonality: Atmospheric and Oceanic Physical Processes Contributions

Author

Ibrahima Camara, Teresa Losada, Alban Lazar, Juliette Mignot, Nicolas Kolodziejczyk, Laboratoire de Physique de l'Atmosphère et de l'Océan Siméon Fongang (LPAO-SF), École Supérieure Polytechnique de Dakar (ESP), Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD)-Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD), Océan et variabilité du climat (VARCLIM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Departamento Fisica de la Tierra, Astronomía y Astrofísica [Madrid], Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), 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), and Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)

Subjects
salt and heat budget, Atmospheric Science, Buoyancy, 010504 meteorology & atmospheric sciences, Mixed layer, Equator, Flux, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Environmental Science (miscellaneous), engineering.material, lcsh:QC851-999, Atmospheric sciences, Convergence zone, 01 natural sciences, Latitude, compensation, 14. Life underwater, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, density, 010505 oceanography, Física atmosférica, Ocean general circulation model, 6. Clean water, Heat flux, physical processes, 13. Climate action, engineering, Environmental science, lcsh:Meteorology. Climatology
Abstract

This study investigates the physical processes controlling the mixed layer buoyancy using a regional configuration of an ocean general circulation model. Processes are quantified by using a linearized equation of state, a mixed-layer heat, and a salt budget. Model results correctly reproduce the observed seasonal near-surface density tendencies. The results indicate that the heat flux is located poleward of 10&deg, of latitude, which is at least three times greater than the freshwater flux that mainly controls mixed layer buoyancy. During boreal spring-summer of each hemisphere, the freshwater flux partly compensates the heat flux in terms of buoyancy loss while, during the fall-winter, they act together. Under the seasonal march of the Inter-tropical Convergence Zone and in coastal areas affected by the river, the contribution of ocean processes on the upper density becomes important. Along the north Brazilian coast and the Gulf of Guinea, horizontal and vertical processes involving salinity are the main contributors to an upper water change with a contribution of at least twice as much the temperature. At the equator and along the Senegal-Mauritanian coast, vertical processes are the major oceanic contributors. This is mainly due to the vertical gradient of temperature at the mixed layer base in the equator while the salinity one dominates along the Senegal-Mauritania coast.

Published
2020
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5. Assessing the Cadmium Effects on the Benthic Foraminifer Ammonia cf. parkinsoniana: An Acute Toxicity Test

Author

Carla Bucci, María Teresa Losada Ros, Eqbal Al-Enezi, Erica Cesarini, Fabrizio Frontalini, Maria Virgínia Alves Martins, Stefano Papa, and Barbara Canonico

Subjects
lcsh:Hydraulic engineering, 010504 meteorology & atmospheric sciences, cadmium, confocal images, Biomagnification, Geography, Planning and Development, chemistry.chemical_element, benthic foraminifera, 010501 environmental sciences, Aquatic Science, 01 natural sciences, Biochemistry, ecotoxicology, chemistry.chemical_compound, lcsh:Water supply for domestic and industrial purposes, lcsh:TC1-978, Ecotoxicology, Bioassay, 0105 earth and related environmental sciences, Water Science and Technology, Cadmium, lcsh:TD201-500, Nile red, Acute toxicity, chemistry, Environmental chemistry, Bioaccumulation, Seawater
Abstract

Heavy metals are one of the most hazardous pollutants in marine environments because of their bioaccumulation and biomagnification capabilities. Among them, cadmium (Cd) has been considered as one of the most dangerous for marine organisms. Here we incubated Ammonia cf. parkinsoniana specimens, a benthic foraminiferal taxon used in previous experiments, for up to 48 h in natural seawater with different concentrations of Cd to unravel the physiological change. We document a reduced pseudopodial activity of the Cd-treated specimens at concentrations &gt, 10&ndash, 100 ppb in comparison with the control specimens. Moreover, confocal images of Cd-treated specimens using Nile Red as a fluorescent probe reveal an enhanced intracellular neutral lipid accumulation in the form of lipid droplets at 6 h and 12 h. This bioassay experiment allows for the direct evaluation of Cd-dose to A. cf. parkinsoniana-response relationships under laboratory controlled conditions and provides complementary information to field observations as well as to water quality guidelines and thresholds.

Published
2020

6. Benthic foraminiferal ultrastructural alteration induced by heavy metals

Author

Ana Martín-González, Rodolfo Coccioni, Fabrizio Frontalini, Alessandra Negri, Anna Sabbatini, Davide Curzi, Pietro Gobbi, Maria Teresa Losada, Maria Pia Nardelli, and Joan M. Bernhard

Subjects
010504 meteorology & atmospheric sciences, Chemistry, Paleontology, chemistry.chemical_element, Residual body, Vacuole, 010501 environmental sciences, Oceanography, 01 natural sciences, Mercury (element), Benthic zone, Lipid droplet, Bioaccumulation, Environmental chemistry, Organelle, Ultrastructure, Protist Pollution Miliolid Ultrastructure Cytoplasm Ammonia Pseudotriloculina, 0105 earth and related environmental sciences
Abstract

Heavy metals are known to cause deleterious effects on biota because of their toxicity, persistence and bioaccumulation. Here, we briefly document the ultrastructural changes observed in the miliolid foraminifer Pseudotriloculina rotunda (d'Orbigny in Schlumberger, 1893) and in the perforate calcareous species Ammonia parkinsoniana (d'Orbigny, 1839) induced by exposure to one of three heavy metals (zinc, lead, or mercury). The exposure of these two benthic foraminiferal species to the selected heavy metals appears to promote cytological alterations and organelle degeneration. These alterations include a thickening of the inner organic lining, an increase in number and size of lipid droplets, mitochondrial degeneration, and degradation vacuoles and residual body proliferation. Some of these alterations, including the thickening of the inner organic lining and the proliferation of lipids, might represent defense mechanisms against heavy metal-induced stress.

Published
2018
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7. Ocean dynamics shapes the structure and timing of Atlantic eequatorial modes

Author

Alban Lazar, Irene Polo, Belén Rodríguez-Fonseca, Marta Martín-Rey, Teresa Losada, Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique (CERFACS), 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), Departamento Fisica de la Tierra, Astronomía y Astrofísica [Madrid], Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), ANR-13-SENV-0002,MORDICUS,Oscillations et rétroactions climatiques aux échelles décennales : mécanismes, sensibilité et incertitudes(2013), European Project: 603521,EC:FP7:ENV,FP7-ENV-2013-two-stage,PREFACE(2013), European Project: 797236,FESTIVAL, European Project: 817578,TRIATLAS(2019), CERFACS, 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)

Subjects
010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], 0207 environmental engineering, 02 engineering and technology, Oceanography, 01 natural sciences, Physics::Geophysics, symbols.namesake, Geochemistry and Petrology, Downwelling, Earth and Planetary Sciences (miscellaneous), 14. Life underwater, 020701 environmental engineering, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Tropical Atlantic Variability, Física atmosférica, Rossby wave, Westerlies, Ocean dynamics, Geophysics, 13. Climate action, Space and Planetary Science, Climatology, Physics::Space Physics, symbols, Upwelling, Thermocline, Kelvin wave, Geology
Abstract

International audience; A recent study has brought to light the co‐existence of two distinct Atlantic Equatorial Modes during negative phases of the Atlantic Multidecadal Variability: the Atlantic Niño and Horse‐Shoe (HS) mode. Nevertheless, the associated air‐sea interactions for HS mode have not been explored so far and the prevailing dynamic view of the Atlantic Niño has been questioned. Here, using a forced ocean model simulation, we find that for both modes, ocean dynamics is essential to explain the equatorial SST variations, while air‐sea fluxes control the off‐equatorial SST anomalies. Moreover, we demonstrate the key role played by ocean waves in shaping their distinct structure and timing. For the positive phase of both Atlantic Niño and HS, anomalous westerly winds trigger a set of equatorial downwelling Kelvin waves (KW) during spring‐summer. These dKWs deepen the thermocline, favouring the equatorial warming through vertical diffusion and horizontal advection. Remarkably, for the HS, an anomalous north‐equatorial wind stress curl excites an upwelling Rossby wave (RW), which propagates westward and is reflected at the western boundary becoming an equatorial upwelling KW. The uKW propagates to the east, activating the thermocline feedbacks responsible to cool the sea surface during summer months. This RW‐reflected mechanism acts as a negative feedback causing the early termination of the HS mode. Our results provide an improvement in the understanding of the TAV modes and emphasize the importance of ocean wave activity to modulate the equatorial SST variability. These findings could be very useful to improve the prediction of the Equatorial Modes.

Published
2019
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8. Foraminiferal ultrastructure: a perspective from fluorescent and fluorogenic probes

Author

L. J. de Nooijer, Jarosław Tyszka, Remi Tsubaki, Rodolfo Coccioni, Maria Teresa Losada, Fabrizio Frontalini, C. Besteiro Rodriguez, Erica Cesarini, Joan M. Bernhard, Jelle Bijma, Eqbal Al-Enezi, Takashi Toyofuku, Ulf Bickmeyer, Tetsuro Ikuta, Barbara Canonico, Jan Goleń, Stefano Papa, and Yukiko Nagai

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, Ecology, Vesicle, Paleontology, Soil Science, Forestry, Aquatic Science, Golgi apparatus, 01 natural sciences, Fluorescence, symbols.namesake, Foraminifera [hole bearers], Lipid droplet, Organelle, Microscopy, Biophysics, Ultrastructure, symbols, Viability assay, 0105 earth and related environmental sciences, Water Science and Technology
Abstract

Microscopy techniques have been widely applied to observe cellular ultrastructure. Most of these techniques, such as transmission electron microscopy, produce high‐resolution images, but they may require extensive preparation, hampering their application for in vivo examination. Other approaches, such as fluorescent and fluorogenic probes, can be applied not only to fixed specimens but also to living cells when the probes are nontoxic. Fluorescence‐based methods, which are generally relatively easy to use, allow visual and (semi)quantitative studies of the ultrastructural organization and processes of the cell under natural as well as manipulated conditions. To date, there are relatively few published studies on the nearly ubiquitous marine protistan group Foraminifera that have used fluorescent and fluorogenic probes, despite their huge potential. The aim of the present contribution is to document the feasible application of a wide array of these probes to foraminiferal biology. More specifically, we applied fluorescence‐based probes to study esterase activity, cell viability, calcium signaling, pH variation, reactive oxygen species, neutral and polar lipids, lipid droplets, cytoskeleton structures, Golgi complex, acidic vesicles, nuclei, and mitochondria in selected foraminiferal species.

Published
2019

9. Impact of climate change on solar irradiation and variability over the Iberian Peninsula using regional climate models

Author

Teresa Losada, Miguel Ángel Gaertner, Victoria Gil, and Claudia Gutiérrez

Subjects
Atmospheric Science, geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, business.industry, 020209 energy, Física atmosférica, Climate change, 02 engineering and technology, Solar energy, 01 natural sciences, Renewable energy, Peninsula, Climatology, Solar Resource, 0202 electrical engineering, electronic engineering, information engineering, Environmental science, Spatial variability, Climate model, business, Solar power, 0105 earth and related environmental sciences
Abstract

As solar energy will be an increasingly important renewable energy source in the future years, the study of how climate change affects both temporal and spatial variability is very important. In this paper, we study future changes of the solar radiation resource in the Iberian Peninsula (IP) through a set of simulations from ESCENA project until mid-century. The evaluation of the simulations against observations indicates contrasting biases for the different regional climate models (RCMs) in terms of solar irradiation amount and its interannual variability. We propose a diagnostic for the quality of solar energy resource, in which the gridpoints are classified in four categories depending on the combination of solar irradiation amount and variability. The observed large percentage of points in the optimal category (high irradiation/low variability) in the IP is captured by the RCMs in general terms. The analysis of scenarios indicates a future increase in solar irradiation, although not all scenarios agree in the geographical distribution of this increase. In most projections, a shift is projected from the category with optimal resource quality towards the category with high irradiation/high variability, pointing to a certain quality loss in the solar resource. This result is not general, as a few scenarios show an opposite result. The exceptions are not linked to a particular GCM or emissions scenario. Finally, results from a first approximation to the issue of the ability of solar energy to cover power demand peaks in summer show important differences between regions of the IP. The spatially-averaged correlation of solar irradiation and summer surface temperatures for the whole IP is rather high, which is a positive result as the strong interconnections of the power grid within the IP could allow a distribution of solar power surpluses in certain regions for such high-temperature episodes.

Published
2019

10. Equatorial Atlantic variability—Modes, mechanisms, and global teleconnections

Author

Irene Polo, Noel Keenlyside, Belén Rodríguez-Fonseca, Marta Martín-Rey, Ingo Richter, Teresa Losada, Joke F. Lübbecke, European Commission, Ministerio de Economía y Competitividad (España), Lübbecke, Joke F., and Lübbecke, Joke F. [0000-0002-7839-3284]

Subjects
Atmospheric Science, Global and Planetary Change, Atlantic Niños, 010504 meteorology & atmospheric sciences, Geography, Planning and Development, Climate system, Mode (statistics), Climate change, Context (language use), Tropical Atlantic, 010502 geochemistry & geophysics, 01 natural sciences, Climate models, Sea surface temperature, Geography, 13. Climate action, Climatology, Climate model, Climate variability, 0105 earth and related environmental sciences, Teleconnection
Abstract

Sea surface temperature (SST) variability in the tropical Atlantic Ocean strongly impacts the climate on the surrounding continents. On interannual time scales, highest SST variability occurs in the eastern equatorial region and off the coast of southwestern Africa. The pattern of SST variability resembles the Pacific El Niño, but features notable differences, and has been discussed in the context of various climate modes, that is, reoccurring patterns resulting from particular interactions in the climate system. Here, we attempt to reconcile those different definitions, concluding that almost all of them are essentially describing the same mode that we refer to as the “Atlantic Niño.” We give an overview of the mechanisms that have been proposed to underlie this mode, and we discuss its interaction with other climate modes within and outside the tropical Atlantic. The impact of Atlantic Niño‐related SST variability on rainfall, in particular over the Gulf of Guinea and north eastern South America is also described. An important aspect we highlight is that the Atlantic Niño and its teleconnections are not stationary, but subject to multidecadal modulations. Simulating the Atlantic Niño proves a challenge for state‐of‐the‐art climate models, and this may be partly due to the large mean state biases in the region. Potential reasons for these model biases and implications for seasonal prediction are discussed., N.S.K., B.R.F., M.M.R., and I.P. benefited from funding from the EU FP7/2007‐2013 PREFACE Project (grant 603521). T.L. is supported with funds from the MINECO under the Juan de la Cierva‐Incorporación Programme (IJCI‐2015‐26645).

Published
2018
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11. Is There Evidence of Changes in Tropical Atlantic Variability Modes under AMO Phases in the Observational Record?

Author

Marta Martín-Rey, Teresa Losada, Irene Polo, Alban Lazar, Belén Rodríguez-Fonseca, Departamento Fisica de la Tierra, Astronomía y Astrofísica [Madrid], Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Processus de la variabilité climatique tropicale et impacts (PARVATI), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), MINNECO project CGL2012-38923-C02-01, European Project: 603521,EC:FP7:ENV,FP7-ENV-2013-two-stage,PREFACE(2013), 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)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636))

Subjects
Atmospheric Science, Atmosphere-ocean interaction, 010504 meteorology & atmospheric sciences, Tropical Atlantic Variability, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Tropical variability, Tropical Atlantic, 010502 geochemistry & geophysics, 01 natural sciences, Sea surface temperature, Interannual variability, Atlantic Equatorial mode, Oceanography, 13. Climate action, Climatology, Teleconnections, Atlantic multidecadal oscillation, Multidecadal variability, ENSO, Thermocline, Horse latitudes, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Teleconnection
Abstract

The Atlantic multidecadal oscillation (AMO) is the leading mode of Atlantic sea surface temperature (SST) variability at multidecadal time scales. Previous studies have shown that the AMO could modulate El Niño–Southern Oscillation (ENSO) variance. However, the role played by the AMO in the tropical Atlantic variability (TAV) is still uncertain. Here, it is demonstrated that during negative AMO phases, associated with a shallower thermocline, the eastern equatorial Atlantic SST variability is enhanced by more than 150% in boreal summer. Consequently, the interannual TAV modes are modified. During negative AMO, the Atlantic Niño displays larger amplitude and a westward extension and it is preceded by a simultaneous weakening of both subtropical highs in winter and spring. In contrast, a meridional seesaw SLP pattern evolving into a zonal gradient leads the Atlantic Niño during positive AMO. The north tropical Atlantic (NTA) mode is related to a Scandinavian blocking pattern during winter and spring in negative AMO, while under positive AMO it is part of the SST tripole associated with the North Atlantic Oscillation. Interestingly, the emergence of an overlooked variability mode, here called the horseshoe (HS) pattern on account of its shape, is favored during negative AMO. This anomalous warm (cool) HS surrounding an eastern equatorial cooling (warming) is remotely forced by an ENSO phenomenon. During negative AMO, the tropical–extratropical teleconnections are enhanced and the Walker circulation is altered. This, together with the increased equatorial SST variability, could promote the ENSO impacts on TAV. The results herein give a step forward in the better understanding of TAV, which is essential to improving its modeling, impacts, and predictability.

Published
2018
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12. Impact of dynamical regionalization on precipitation biases and teleconnections over West Africa

Author

Marta Domínguez, Teresa Losada, Belén Rodríguez-Fonseca, Elsa Mohino, Iñigo Gómara, Roberto Suárez-Moreno, European Commission, and Ministerio de Economía y Competitividad (España)

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, 0208 environmental biotechnology, 02 engineering and technology, Precipitation, Monsoon, 01 natural sciences, West African monsoon, Atlantic Equatorial mode, CMIP5, 0105 earth and related environmental sciences, Intertropical Convergence Zone, Meteorología, Subsidence (atmosphere), Tropical variability, Geofísica, 020801 environmental engineering, Sea surface temperature, CORDEX, 13. Climate action, Climatology, Teleconnections, Environmental science, Climate model, Teleconnection
Abstract

West African societies are highly dependent on the West African Monsoon (WAM). Thus, a correct representation of the WAM in climate models is of paramount importance. In this article, the ability of 8 CMIP5 historical General Circulation Models (GCMs) and 4 CORDEX-Africa Regional Climate Models (RCMs) to characterize the WAM dynamics and variability is assessed for the period July-August-September 1979–2004. Simulations are compared with observations. Uncertainties in RCM performance and lateral boundary conditions are assessed individually. Results show that both GCMs and RCMs have trouble to simulate the northward migration of the Intertropical Convergence Zone in boreal summer. The greatest bias improvements are obtained after regionalization of the most inaccurate GCM simulations. To assess WAM variability, a Maximum Covariance Analysis is performed between Sea Surface Temperature and precipitation anomalies in observations, GCM and RCM simulations. The assessed variability patterns are: El Niño-Southern Oscillation (ENSO); the eastern Mediterranean (MED); and the Atlantic Equatorial Mode (EM). Evidence is given that regionalization of the ENSO–WAM teleconnection does not provide any added value. Unlike GCMs, RCMs are unable to precisely represent the ENSO impact on air subsidence over West Africa. Contrastingly, the simulation of the MED–WAM teleconnection is improved after regionalization. Humidity advection and convergence over the Sahel area are better simulated by RCMs. Finally, no robust conclusions can be determined for the EM–WAM teleconnection, which cannot be isolated for the 1979–2004 period. The novel results in this article will help to select the most appropriate RCM simulations to study WAM teleconnections., This study has been supported by the European Commission’s research project PREFACE (EU/FP7 2007–2013; ref. 603521). Iñigo Gómara is also supported by the Spanish Ministry of Economy and Competitiveness (“Juan de la Cierva-Formación” contract; FJCI-2015-23874).

Published
2018

13. Assessing the effect of mercury pollution on cultured benthic foraminifera community using morphological and eDNA metabarcoding approaches

Author

Maria Pia Nardelli, Mattia Greco, Emanuela Reo, Claudia Cosentino, Rodolfo Coccioni, Franck Lejzerowicz, Giovanna Scopelliti, Maria Teresa Losada, Fabrizio Frontalini, Letizia Di Bella, Jan Pawlowski, Antonella Maccotta, Eric Armynot du Châtelet, Antonio Caruso, Frontalini, F., Greco, M., Di Bella, L., Lejzerowicz, F., Reo, E., Caruso, A., Cosentino, C., Maccotta, A., Scopelliti, G., Nardelli M., P., Losada M., T., Armynot Du Châtelet, Coccioni, R., and Pawlowski, J.

Subjects
0301 basic medicine, Pollution, mercury pollution, Geologic Sediments, media_common.quotation_subject, benthic foraminifera, Benthic foraminifera, Biomonitoring, Mercury pollution, Metabarcoding, Foraminifera, 010501 environmental sciences, Aquatic Science, Oceanography, 01 natural sciences, Mesocosm, 03 medical and health sciences, Biomonitoring, Mediterranean Sea, DNA Barcoding, Taxonomic, Environmental DNA, Seawater, metabarcoding biomonitoring, 0105 earth and related environmental sciences, media_common, biology, Ecology, Benthic foraminifera, Biodiversity, Mercury, DNA, Protozoan, Mercury pollution, biology.organism_classification, Metabarcoding, 030104 developmental biology, Italy, 13. Climate action, Benthic zone, Bioaccumulation, Bioindicator, Water Pollutants, Chemical, Environmental Monitoring
Abstract

Mercury (Hg) is a highly toxic element for living organisms and is known to bioaccumulate and biomagnify. Here, we analyze the response of benthic foraminifera communities cultured in mesocosm and exposed to different concentrations of Hg. Standard morphological analyses and environmental DNA metabarcoding show evidence that Hg pollution has detrimental effects on benthic foraminifera. The molecular analysis provides a more complete view of foraminiferal communities including the soft-walled single-chambered monothalamiids and small-sized hard-shelled rotaliids and textulariids than the morphological one. Among these taxa that are typically overlooked in morphological studies we found potential bioindicators of Hg pollution. The mesocosm approach proves to be an effective method to study benthic foraminiferal responses to various types and concentrations of pollutants over time. This study further supports foraminiferal metabarcoding as a complementary and/or alternative method to standard biomonitoring program based on the morphological identification of species communities.

Published
2018

14. Revisiting the CMIP5 Thermocline in the Equatorial Pacific and Atlantic Oceans

Author

Belén Rodríguez-Fonseca, Antonio Castaño-Tierno, Teresa Losada, Elsa Mohino, European Commission, Ministerio de Economía y Competitividad (España), Castaño-Tierno, Antonio [0000-0002-4469-5292], Mohino, E. [0000-0002-4342-6349], Rodríguez-Fonseca, Belén [0000-0002-5261-7083], Losada, T. [0000-0002-8430-1745], Castaño-Tierno, Antonio, Mohino, E., Rodríguez-Fonseca, Belén, and Losada, T.

Subjects
010504 meteorology & atmospheric sciences, Simple Ocean Data Assimilation, Kuroshio intrusion, Wind stress, 010502 geochemistry & geophysics, 01 natural sciences, Equatorial ocean, Thermocline, 14. Life underwater, 0105 earth and related environmental sciences, Coupled model intercomparison project, Física atmosférica, 16. Peace & justice, Annual cycle, Northern South China Sea, Current (stream), Temperature gradient, Geophysics, Oceanography, 13. Climate action, General Circulation Model, Model biases, General Earth and Planetary Sciences, Geology
Abstract

The thermocline is defined as the ocean layer for which the vertical thermal gradient is maximum. In the equatorial ocean, observations led to the use of the 20 °C isotherm depth (z20) as an estimate of the thermocline. This study compares z20 against the physical thermocline in the equatorial Atlantic and Pacific Oceans, using Simple Ocean Data Assimilation reanalysis and fifth phase of the Coupled Model Intercomparison Project preindustrial control simulations. Our results show that z20 is systematically deeper and flatter than the thermocline and does not respond correctly to surface wind stress variations. It is also shown that the annual cycle of z20 is much weaker than that of the physical thermocline. This happens in both equatorial basins and indicates that z20 does not react to the same mechanisms as the thermocline. This could have important consequences in the assessment of air‐sea coupling in current general circulation models and bias reduction strategies., The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement 603521 (PREFACE project) and from the Spanish Ministry of Science (Project PRE4CAST, CGL2017‐86415‐R).

Published
2018

15. Tropical atmospheric response to decadal changes in the Atlantic Equatorial Mode

Author

Teresa Losada, Belén Rodríguez-Fonseca, and Ministerio de Economía y Competitividad (España)

Subjects
Tropical pacific, Atmospheric Science, 010504 meteorology & atmospheric sciences, Mode (statistics), Tropical Atlantic, 010502 geochemistry & geophysics, 01 natural sciences, Atmosphere, Sea surface temperature, Equatorial mode, Tropical teleconnections, Atlantic Equatorial mode, 13. Climate action, Climatology, Walker circulation, Climate model, Climate variability, Geology, 0105 earth and related environmental sciences
Abstract

It has been shown that the atmospheric response to the Atlantic Equatorial Mode is non-stationary. After the 1970s, Sea Surface Temperature (SST) anomalies in the tropical Atlantic are able to alter the atmosphere in the tropical Pacific via modifications of the Walker circulation. Such changes could be related to the differences in the background state of the global SSTs before and after the 1970s, but also to changes in the interannual Equatorial Mode itself. In this work we first describe the differences in the interannual Equatorial Mode before and after the 1970s. Then we use two AGCMs to perform different sensitivity experiments changing the spatial structure of the Equatorial Mode, and we explore the differences in the atmospheric response over the tropical Pacific region to each of the SST patterns considered. It is shown that the changes in the Walker Atlantic–Pacific cell produced by the EM are stronger after the 1970s, and are reinforced by the change in the impact of the EM over the Indian Ocean and the Maritime Continent. It is also shown that, although the Atlantic–Pacific connection is established by the aforementioned changes in the Walker circulation between the two basins, the modulation of the Indian sector is crucial for a realistic simulation of such connection by climate models., The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under Grant Agreement No. 603521 (PREFACE Project), and by the Spanish Project CGL2012-38923-C02-01.

Published
2015
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16. Multidecadal Modulation of ENSO Teleconnection with Europe in Late Winter: Analysis of CMIP5 Models

Author

Teresa Losada, Belén Rodríguez de Fonseca, Jorge López Parages, and Elsa Mohino

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, Rossby wave, Precipitation, Jet stream, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, Rossby waves, Troposphere, Sea surface temperature, Interannual variability, El Niño Southern Oscillation, Climatology, Modulation (music), Environmental science, Multidecadal variability, ENSO, 0105 earth and related environmental sciences, Teleconnection, Coupled models
Abstract

Many studies point to a robust ENSO signature on the North Atlantic–European (NAE) sector associated with a downstream effect of Rossby wave trains. Some of these works also address a nonstationary behavior of the aforementioned link, but only few have explored the possible modulating factors. In this study the internal causes within the ocean–atmosphere coupled system influencing the tropospheric ENSO–Euro-Mediterranean rainfall teleconnection have been analyzed. To this aim, unforced long-term preindustrial control simulations from 18 different CMIP5 models have been used. A nonstationary impact of ENSO on Euro-Mediterranean rainfall, being spatially consistent with the observational one, is found. This variable feature is explained by a changing ENSO-related Rossby wave propagation from the tropical Pacific to the NAE sector, which, in turn, is modulated by multidecadal variability of the climatological jet streams associated with the underlying sea surface temperature (SST). The results, therefore, indicate a modulation of the ENSO–Euro-Mediterranean rainfall teleconnection by the internal (and multidecadal) variability of the ocean–atmosphere coupled system., This study was supported by the European project PREFACE (603521), and the Spanish projects TRACS (CGL2009-10285) and MULCLIVAR (CGL2012- 38923-C02-01).

Published
2016

17. The Teleconnection of the Tropical Atlantic to Indo-Pacific Sea Surface Temperatures on Inter-Annual to Centennial Time Scales: A Review of Recent Findings

Author

Carlos R. Mechoso, Belén Rodríguez-Fonseca, Fred Kucharski, Riccardo Farneti, Afroja Parvin, Irene Polo, Teresa Losada, Marta Martín-Rey, and Elsa Mohino

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, teleconnections, Environmental Science (miscellaneous), Tropical Atlantic, lcsh:QC851-999, 010502 geochemistry & geophysics, 01 natural sciences, Atlantic Niño, Atlantic multidecadal oscillation, Atlantic Equatorial mode, Downwelling, 0105 earth and related environmental sciences, ENSO predictability, Meteorología, Física atmosférica, pacific decadal variability, Geofísica, Sea surface temperature, La Niña, Oceanography, Climatology, lcsh:Meteorology. Climatology, Geology, Indo-Pacific, Teleconnection
Abstract

In this paper, the teleconnections from the tropical Atlantic to the Indo-Pacific region from inter-annual to centennial time scales will be reviewed. Identified teleconnections and hypotheses on mechanisms at work are reviewed and further explored in a century-long pacemaker coupled ocean-atmosphere simulation ensemble. There is a substantial impact of the tropical Atlantic on the Pacific region at inter-annual time scales. An Atlantic Nino (Nina) event leads to rising (sinking) motion in the Atlantic region, which is compensated by sinking (rising) motion in the central-western Pacific. The sinking (rising) motion in the central-western Pacific induces easterly (westerly) surface wind anomalies just to the west, which alter the thermocline. These perturbations propagate eastward as upwelling (downwelling) Kelvin-waves, where they increase the probability for a La Nina (El Nino) event. Moreover, tropical North Atlantic sea surface temperature anomalies are also able to lead La Nina/El Nino development. At multidecadal time scales, a positive (negative) Atlantic Multidecadal Oscillation leads to a cooling (warming) of the eastern Pacific and a warming (cooling) of the western Pacific and Indian Ocean regions. The physical mechanism for this impact is similar to that at inter-annual time scales. At centennial time scales, the Atlantic warming induces a substantial reduction of the eastern Pacific warming even under CO_2 increase and to a strong subsurface cooling.

Published
2016

18. A Review of ENSO Influence on the North Atlantic. A Non-Stationary Signal

Author

Antonio Castaño-Tierno, Jorge López-Parages, Elsa Mohino, Julián Villamayor, Roberto Suárez-Moreno, Iñigo Gómara, Blanca Ayarzagüena, Teresa Losada, Belén Rodríguez-Fonseca, Ministerio de Economía y Competitividad (España), and Consejo Superior de Investigaciones Científicas (España)

Subjects
Atmospheric Science, El Niño-Southern Oscillation, non-stationarity, 010504 meteorology & atmospheric sciences, Western African Monsoon, teleconnections, Euro-Mediterranean rainfall, Environmental Science (miscellaneous), lcsh:QC851-999, 010502 geochemistry & geophysics, Monsoon, 01 natural sciences, Atlantic Equatorial mode, Atlantic multidecadal oscillation, Extratropical cyclone, 0105 earth and related environmental sciences, Atlantic hurricane, Stratosphere, Non-stationarity, Multivariate ENSO index, Atlantic Multidecadal Oscillation, Geofísica, Hurricanes, Oceanography, 13. Climate action, North Atlantic oscillation, Climatology, Teleconnections, stratosphere, Environmental science, North Atlantic region, hurricanes, lcsh:Meteorology. Climatology, North Atlantic Oscillation, Teleconnection
Abstract

The atmospheric seasonal cycle of the North Atlantic region is dominated by meridional movements of the circulation systems: from the tropics, where the West African Monsoon and extreme tropical weather events take place, to the extratropics, where the circulation is dominated by seasonal changes in the jetstream and extratropical cyclones. Climate variability over the North Atlantic is controlled by various mechanisms. Atmospheric internal variability plays a crucial role in the mid-latitudes. However, El Niño-Southern Oscillation (ENSO) is still the main source of predictability in this region situated far away from the Pacific. Although the ENSO influence over tropical and extra-tropical areas is related to different physical mechanisms, in both regions this teleconnection seems to be non-stationary in time and modulated by multidecadal changes of the mean flow. Nowadays, long observational records (greater than 100 years) and modeling projects (e.g., CMIP) permit detecting non-stationarities in the influence of ENSO over the Atlantic basin, and further analyzing its potential mechanisms. The present article reviews the ENSO influence over the Atlantic region, paying special attention to the stability of this teleconnection over time and the possible modulators. Evidence is given that the ENSO–Atlantic teleconnection is weak over the North Atlantic. In this regard, the multidecadal ocean variability seems to modulate the presence of teleconnections, which can lead to important impacts of ENSO and to open windows of opportunity for seasonal predictability., Research projects PREFACE (EUFP7/2007-2013 Grant Agreement 603521) and MULCLIVAR (CGL2012-38923-C02-01-Spanish Ministry of Economy and Competitiveness)

Published
2016

19. Tropical response to the Atlantic Equatorial mode: AGCM multimodel approach

Author

Irene Polo, Sébastien Gervois, Paolo Ruti, Serge Janicot, Teresa Losada, Fabrice Chauvin, Belén Rodríguez-Fonseca, Departamento de Geofisica y Meteorologia [Madrid], Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)

Subjects
Monsoon of South Asia, Atmospheric Science, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDE.MCG]Environmental Sciences/Global Changes, Intertropical Convergence Zone, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 010502 geochemistry & geophysics, Monsoon, 01 natural sciences, La Niña, Atlantic Equatorial mode, Oceanography, 13. Climate action, Climatology, East Asian Monsoon, Walker circulation, Geology, 0105 earth and related environmental sciences, Teleconnection
Abstract

International audience; On the frame of the AMMA-EU project, sensitivity experiments for an Atlantic Equatorial mode (AEM) which origin, development and damping resembles the observed one during the last decades of the 20th century, has been analysed in order to investigate the influence on the anomalous summer West African rainfall. Recent studies raise the matter of the AEM influence on the next Pacific ENSO episodes and also on the Indian Monsoon. This paper evaluates the response of four different atmospheric global circulation models, using the above-mentioned AEM sensitivity experiments, to study the tropical forcing associated with the Atlantic Niño mode. The results show a remote signal in both the Pacific and Indian basins. For a warm phase of the AEM the associated southward location of the ITCZ, with rising motions over the Equatorial Atlantic, leads to a global subsidence over the rest of the tropics, weakening the Asian Monsoon and favouring the La Niña conditions in the central Pacific. Although ocean-atmosphere coupled experiments are required to test the latter hypothesis, the present studies shows how the AEM is able to influence the rest of the tropics, a result with important implications on ENSO seasonal predictability.

Published
2009
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20. Impacts of the Atlantic Equatorial Mode in a warmer climate

Author

Teresa Losada and Elsa Mohino

Subjects
Monsoon of South Asia, Atmospheric Science, 010504 meteorology & atmospheric sciences, Tropical Atlantic Variability, Meteorología, Climate change, Tropical Atlantic, Geofísica, 010502 geochemistry & geophysics, 01 natural sciences, Sea surface temperature, Atlantic Equatorial mode, Oceanography, 13. Climate action, Climatology, Atlantic multidecadal oscillation, East Asian Monsoon, Geology, 0105 earth and related environmental sciences
Abstract

The main source of sea surface temperature (SST) variability in the Tropical Atlantic at interannual time scales is the Equatorial Mode or Atlantic El Niño. It has been shown to affect the adjacent continents and also remote regions, leading to a weakened Indian Monsoon and promoting La Niña-type anomalies over the Pacific. However, its effects in a warmer climate are unknown. This work analyses the impact of the Equatorial Mode at the end of the twenty first century by means of sensitivity experiments with an atmosphere general circulation model. The prescribed boundary conditions for the future climate are based on the outputs from models participating in the coupled model intercomparison project-phase V. Our results suggest that even if the characteristics of the Equatorial Mode at the end of the twenty first century remained equal to those of the twentieth century, there will be an eastward shift of the main rainfall positive anomalies in the Tropical Atlantic and a weakening of the negative rainfall anomalies over the Asian monsoon due to the change in climatological SSTs. We also show that extratropical surface temperature anomalies over land related to the mode will change in regions like Southwestern Europe, East Australia, Asia or North America due to the eastward shift of the sea level pressure systems and related surface winds.

Published
2015

21. The non-stationary influence of the Atlantic and Pacific Niños on North Eastern South American rainfall

Author

Verónica Torralba, Belén Rodríguez-Fonseca, Elsa Mohino, Teresa Losada, and European Commission

Subjects
010504 meteorology & atmospheric sciences, interannual variability, atmosphere general circulation models, Intertropical Convergence Zone, SST forced response, Forcing (mathematics), Tropical Atlantic, 010502 geochemistry & geophysics, 01 natural sciences, multidecadal modulations, Atlantic Equatorial mode, Oceanography, 13. Climate action, Climatology, Atlantic multidecadal oscillation, Period (geology), General Earth and Planetary Sciences, Earth Science, Predictability, Tropical cyclone rainfall forecasting, Geology, Northeastern South America rainfall, 0105 earth and related environmental sciences
Abstract

Rainfall variability over the tropical Atlantic region is dominated by changes in the surface temperature of the surrounding oceans. In particular, the oceanic forcing over Northeast of South America is dominated by the Atlantic interhemispheric temperature gradient, which leads its predictability. Nevertheless, in recent decades, the SST influence on rainfall variability in some tropical Atlantic regions has been found to be non-stationary, with important changes of the Atlantic and Pacific influence on Sahelian rainfall which appear to be modulated at multidecadal timescales. In this work, we revisit the SST influence over Northeast of South America including the analysis of the stationarity of this relationship at interannual timescales. Principal Component Analysis has been applied to the interannual component of rainfall during the March-April-May season. Results show how the SST forcing on the first mode of rainfall variability, which is a dipole-like pattern generated by the changes in the seasonal migration of the Intertropical Convergence Zone, is different depending of the considered period. The response to the SST anomalies in the Pacific basin is opposite to the Atlantic one and affects different areas. The Atlantic Niño influences rainfall variability at the beginning of the XX century and after 1970, while the Pacific Niño plays a major role in the variability of the rainfall in the Northeast of South America from 1970 onwards. The combined effect of both basins after the 1970s amplifies the anomalous rainfall response., The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement n° 603521 (PREFACE project) and the Spanish project CGL2012-38923-C02-01.

Published
2015

22. Can reducing the incoming energy flux over the Southern Ocean in a CGCM improve its simulation of tropical climate?

Author

Timothy A. Myers, Teresa Losada, Carlos R. Mechoso, Elsa Mohino-Harris, Shunya Koseki, Belén Rodríguez-Fonseca, Antonio Castaño-Tierno, Thomas Toniazzo, and Noel Keenlyside

Subjects
010504 meteorology & atmospheric sciences, Meteorology, Intertropical Convergence Zone, Energy flux, 010502 geochemistry & geophysics, 01 natural sciences, Geophysics, 13. Climate action, Climatology, Tropical climate, General Earth and Planetary Sciences, Environmental science, media_common.cataloged_instance, 14. Life underwater, European union, Predictability, 0105 earth and related environmental sciences, media_common
Abstract

NOAA's Climate Program Office, Climate Variability and Predictability Program Award. Grant Number: NA14OAR4310278. European Union Seventh Framework Programme. Grant Numbers: FP7/2007–2013, 60352

Published
2016
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23. Tropical SST and Sahel rainfall: A non-stationary relationship

Author

Serge Janicot, Elsa Mohino, Juergen Bader, Carlos R. Mechoso, Belén Rodríguez-Fonseca, and Teresa Losada

Subjects
Tropical pacific, 010504 meteorology & atmospheric sciences, Tropics, Tropical Atlantic, 010502 geochemistry & geophysics, 01 natural sciences, West africa, Geophysics, Oceanography, 13. Climate action, Climatology, General Circulation Model, General Earth and Planetary Sciences, Precipitation, Tropical cyclone rainfall forecasting, Geology, 0105 earth and related environmental sciences, Teleconnection
Abstract

[1] Sea surface temperature (SST) anomalies in the tropical Atlantic have been associated with precipitation anomalies in West Africa that form a dipole pattern with centers over the Sahel and the Gulf of Guinea. Whilst this was clear before the 1970's, the dipole pattern almost disappeared after that date, as the anti-correlation between rainfall anomalies in the Sahel and Guinea dropped abruptly. Simultaneously, the anti-correlations between Sahel rainfall and tropical Pacific SSTs strengthened. It has been posited that these changes after the 1970's developed as rainfall over West Africa started to co-vary with SSTs in the global tropics. In this co-variability, enhanced summer rainfall over West Africa with a monopole pattern corresponds to warmer SSTs in the tropical Atlantic and Maritime Continent, and colder SSTs in the tropical Pacific and western Indian Oceans. The present paper describes the hitherto unexplored seasonal evolution of this co-variability and the physical mechanisms at work. Sensitivity experiments with two atmospheric general circulation models demonstrate that, after the 1970's, the impacts of SST anomalies in the Indo-Pacific counteract those in the Atlantic in terms of generating rainfall anomalies over the Sahel, and that this superposition of effects is primarily linear. Therefore, at interannual timescales, the change in the patterns of co-variability between West African rainfall and tropical SSTs can explain the non-stationary relationship between the anomalies in these two fields.

Published
2012
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24. Changes in the interannual SST-forced signals on West African rainfall. AGCM intercomparison

Author

Serge Janicot, Teresa Losada, Belén Rodríguez-Fonseca, Paolo Ruti, Juergen Bader, Elsa Mohino, Sébastien Gervois, Fabrice Chauvin, Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL)

Subjects
Mediterranean climate, Atmospheric general circulation models, Atmospheric Science, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Climate shift, West African Monsoon, general circulation models, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 010502 geochemistry & geophysics, Positive correlation, Atmospheric sciences, 01 natural sciences, West africa, West african, Sea surface temperature, 13. Climate action, Interannual climate variability, Climatology, General Circulation Model, Environmental science, Turning point, Atmospheric, 0105 earth and related environmental sciences
Abstract

International audience; Rainfall over West Africa shows strong interannual variability related to changes in Sea Surface Temperature (SST). Nevertheless, this relationship seem to be non-stationary. A particular turning point is the decade of the 1970s, which witnessed a number of changes in the climatic system, including the climate shift of the late 1970s. The first aim of this study is to explore the change in the interannual variability of West African rainfall after this shift. The analysis indicates that the dipolar features of the rainfall variability over this region, related to changes in the Atlantic SST, disappear after this period. Also, the Pacific SST variability has a higher correlation with Guinean rainfall in the recent period. The results suggest that the current relationship between the Atlantic and Pacific El Niño phenomena is the principal responsible for these changes. A fundamental goal of climate research is the development of models simulating a realistic current climate. For this reason, the second aim of this work is to test the performance of Atmospheric General Circulation models in simulating rainfall variability over West Africa. The models have been run with observed SSTs for the common period 1957-1998 as part of an intercomparison exercise. The results show that the models are able to reproduce Guinean interannual variability, which is strongly related to SST variability in the Equatorial Atlantic. Nevertheless, problems in the simulation of the Sahelian interannual variability appear: not all models are able to reproduce the observed negative link between rainfall over the Sahel and El Niño-like anomalies in the Pacific, neither the positive correlation between Mediterranean SSTs and Sahelian rainfall.

Published
2011
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25. The West African climate system: a review of the AMMA model inter-comparison initiatives

Author

Marta Domínguez, Teresa Losada, Filippo Giorgi, Françoise Guichard, Florence Favot, Markku Rummukainen, Jean-Philippe Lafore, P. F. J. van Velthoven, Ionela Musat, Béatrice Josse, J. E. Williams, Miguel Ángel Gaertner, Frédéric Hourdin, Céline Mari, Kathy S. Law, Xin Yang, A. K. Traore, Brice Barret, Jan Polcher, Idir Bouarar, M. B. Rodriguez de Fonseca, Paolo Ruti, Aaron Boone, Yongkang Xue, Energy Environment Modeling Unit-Climate and Impact Modeling Laboratory (UTMEA-CLIM), Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile = Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Royal Netherlands Meteorological Institute (KNMI), Institut Pierre-Simon-Laplace (IPSL), 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)-Université Pierre et Marie Curie - Paris 6 (UPMC)-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)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Swedish Meteorological and Hydrological Institute (SMHI), Instituto de Ciencias Ambientales [Toledo] (ICAM), Universidad de Castilla-La Mancha = University of Castilla-La Mancha (UCLM), Departamento de Geofisica y Meteorologia [Madrid], Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Abdus Salam International Centre for Theoretical Physics [Trieste] (ICTP), Department of Geography [Los Angeles], University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Centre for Atmospheric Science [Cambridge, UK], University of Cambridge [UK] (CAM), Laboratoire de Physique de l'Atmosphère et de l'Océan Siméon Fongang (LPAO-SF), École Supérieure Polytechnique de Dakar (ESP), Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD)-Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD), Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), École normale supérieure - Paris (ENS Paris), Département des Géosciences - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Universidad de Castilla-La Mancha (UCLM), University of California-University of California, Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées

Subjects
2. Zero hunger, Systematic error, Atmospheric Science, 010504 meteorology & atmospheric sciences, Multidisciplinary analysis, [SDE.MCG]Environmental Sciences/Global Changes, Climate system, 0207 environmental engineering, 02 engineering and technology, 15. Life on land, Monsoon, Systematic errors, 01 natural sciences, West africa, West african, Geography, African monsoon, 13. Climate action, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Climatology, 020701 environmental engineering, Regional and global model uncertainties, 0105 earth and related environmental sciences
Abstract

International audience; We review the African Monsoon Multidisciplinary Analysis (AMMA) model inter-comparison activities for West Africa. The Model Inter-comparison Project is an evaluation exercise of how global and regional atmospheric models represent seasonal and intra-seasonal variations of the climate and rainfall over the Sahel. The Land surface Model Inter-comparison Project in turn focuses on modelling critical land surface processes over West Africa and on their link with the atmosphere. The CHEmistry Model Inter-comparison Project (CHEMIP) is a comparison of the tropospheric composition as simulated by a number of Chemical Transport Models (CTM) and Chemistry-Climate Models. We highlight the main model limitations and provide recommendations for future development.

Published
2011
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26. A multi-model approach to the Atlantic Equatorial mode: impact on the West African monsoon

Author

Fabrice Chauvin, Sébastien Gervois, Paolo Ruti, Belén Rodríguez-Fonseca, Serge Janicot, Teresa Losada, Departamento de Geofisica y Meteorologia [Madrid], Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDE.MCG]Environmental Sciences/Global Changes, 0207 environmental engineering, West African Monsoon, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 02 engineering and technology, Atmospheric model, Monsoon, 01 natural sciences, Tropical Atlantic variability, Atlantic Equatorial mode, Tropical teleconnections, Precipitation, 020701 environmental engineering, 0105 earth and related environmental sciences, Tropical Atlantic Variability, Mode (statistics), West african, Oceanography, 13. Climate action, Climatology, Geology, Teleconnection
Abstract

International audience; This paper is focused on the West African anomalous precipitation response to an Atlantic Equatorial mode whose origin, development and damping resembles the observed one during the last decades of the XXth century. In the framework of the AMMA-EU project, this paper analyses the atmospheric response to the Equatorial mode using a multimodel approach with an ensemble of integrations from 4 AGCMs under a time varying Equatorial SST mode. The Guinean Gulf precipitation, which together with the Sahelian mode accounts for most of the summer West African rainfall variability, is highly coupled to this Equatorial Atlantic SST mode or Atlantic Niño. In a previous study, done with the same models under 1958-1997 observed prescribed SSTs, most of the models identify the Equatorial Atlantic SST mode as the one most related to the Guinean Gulf precipitation. The models response to the positive phase of equatorial Atlantic mode (warm SSTs) depicts a direct impact in the equatorial Atlantic, leading to a decrease of the local surface temperature gradient, weakening the West African Monsoon flow and the surface convergence over the Sahel.

Published
2010
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27. Interannual and decadal SST-forced responses of the West African monsoon

Author

Paolo Ruti, Sébastien Gervois, Juergen Bader, Belén Rodríguez-Fonseca, Pascal Roucou, Mathieu Joly, Teresa Losada, Elsa Mohino, Bernard Fontaine, Irene Polo, Fabrice Chauvin, Aurore Voldoire, Serge Janicot, Cyril Caminade, Javier García-Serrano, Université Madrid, Université de Madrid, Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Departamento de Álgebra [Madrid], Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Bjerknes Centre for Climate Research (BCCR), Department of Biological Sciences [Bergen] (BIO / UiB), University of Bergen (UiB)-University of Bergen (UiB), Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique (CERFACS), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Centre de Recherches de Climatologie (CRC), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), UCM, Ente per le Nuove tecnologie, l'Energia e l'Ambiente (ENEA), gouvernement italien, Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), CERFACS, Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques ( LOCEAN ), Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Departmento de Álgebra [Madrid] ( UCM ), Universidad Complutense de Madrid [Madrid] ( UCM ), Bjerknes Centre for Climate Research ( BCCR ), University of Bergen ( UIB ), Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique ( CERFACS ), Groupe d'étude de l'atmosphère météorologique ( CNRM-GAME ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Météo France-Centre National de la Recherche Scientifique ( CNRS ), Centre de Recherches de Climatologie ( CRC ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), and Ente per le Nuove tecnologie, l'Energia e l'Ambiente ( ENEA )

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, interannual variability, Multidisciplinary analysis, [SDE.MCG]Environmental Sciences/Global Changes, Global warming, rainfall, 0207 environmental engineering, SST forced response, African Monsoon, 02 engineering and technology, Monsoon, 01 natural sciences, Sea surface temperature, West african, [ SDE.MCG ] Environmental Sciences/Global Changes, 13. Climate action, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Climatology, Sahelian, Environmental science, [ SDU.STU.CL ] Sciences of the Universe [physics]/Earth Sciences/Climatology, 020701 environmental engineering, decadal variability, 0105 earth and related environmental sciences
Abstract

International audience; We review the studies carried out during the African Monsoon Multidisciplinary Analysis (AMMA)-EU on the changes of interannual sea surface temperature (SST)-West African monsoon (WAM) covariability at multidecadal timescales, together with the influence of global warming (GW). The results obtained in the AMMA-EU suggest the importance of the background state, modulated by natural and anthropogenic variability, in the appearance of different interannual modes. The lack of reliability of current coupled models in giving a realistic assessment for WAM in the future is also stated.

Published
2010
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28. Impacts of Warm and Cold situations in the Mediterranean Basins on the West African monsoon: observed connection patterns (1979-2006) and climate simulations

Author

Sébastien Gervois, S. Sijikumar, Pascal Roucou, Paolo Ruti, Serge Janicot, Teresa Losada, Belén Rodríguez-Fonseca, Fabrice Chauvin, Javier García-Serrano, Bernard Fontaine, Centre de Recherches de Climatologie (CRC), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Departamento de Álgebra [Madrid], Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Ente per le Nuove tecnologie, l'Energia e l'Ambiente (ENEA), gouvernement italien, Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-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)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Centre de Recherches de Climatologie ( CRC ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), Departmento de Álgebra [Madrid] ( UCM ), Universidad Complutense de Madrid [Madrid] ( UCM ), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques ( LOCEAN ), Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Groupe d'étude de l'atmosphère météorologique ( CNRM-GAME ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Météo France-Centre National de la Recherche Scientifique ( CNRS ), and Ente per le Nuove tecnologie, l'Energia e l'Ambiente ( ENEA )

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, Intertropical Convergence Zone, [SDE.MCG]Environmental Sciences/Global Changes, 0207 environmental engineering, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 02 engineering and technology, Moisture advection, Monsoon, 01 natural sciences, Mediterranean Basin, [ SDE.MCG ] Environmental Sciences/Global Changes, Sea surface temperature, Mediterranean sea, [ PHYS.PHYS.PHYS-GEO-PH ] Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 13. Climate action, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Climatology, Outgoing longwave radiation, [ SDU.STU.CL ] Sciences of the Universe [physics]/Earth Sciences/Climatology, 020701 environmental engineering, Geology, 0105 earth and related environmental sciences, Teleconnection
Abstract

International audience; Using both empirical and numerical ensemble approaches this study focuses on the Mediterranean / West African relationship in northern summer. Statistical analyses utilize skin temperature, sea surface temperature, in situ and satellite rainfall, Outgoing Longwave Radiation (OLR) observations and reanalyzed data winds and specific humidity on isobaric surfaces. Numerical investigations are based on a large set of sensitivity experiments performed on four Atmospheric General Circulation Models (AGCM): ARPEGE-Climat3, ECHAM4, LMDZ4 and UCLA7.3. Model outputs are compared to observations, discussed model by model and with an ensemble (multi-model) approach. As in previous studies the anomalous Mediterranean warm events are associated with specific impacts over the African monsoon region, i.e., a more intense monsoon, enhanced flux convergence and ascendances around the ITCZ, a strengthening of low level moisture advection and a more northward location of ascending motion in West Africa. The results show also new features (i) thermal variability observed in the two Mediterranean basins has unalike impacts, i.e. the western Mediterranean covaries with convection in Gulf of Guinea, while the eastern Mediterranean can be interpreted as Sahelian thermal-forcing; (ii) although observations show symmetry between warming and cooling, modelling evidences only support the eastern warming influence; (iii) anomalous East warm situations are associated with a more northward migration of the monsoon system accompanied by enhanced southwesterly flow and weakened northeasterly climatological wind; (iv) the multi-model response shows that anomalous East warm surface temperatures generate an enhancement of the overturning circulation in low and high levels, an increase in TEJ (Tropical Easterly Jet) and a decrease in AEJ (African Easterly Jet).

Published
2009
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