Variability and predictability of West African droughts: a review on the role of sea surface temperature anomalies.

• Published in: Journal of Climate
• Main Authors: Rodríguez-Fonseca, Belén, Mohino, Elsa, Mechoso, Carlos R., Caminade, Cyril, Biasutti, Michela, Gaetani, Marco, García-Serrano, Javier, Vizy, Edward K., Cook, Kerry, Xue, Yongkang, Polo, Irene, Losada, Teresa, Druyan, Leonard, Fontaine, Bernard, Bader, Juergen, Doblas-Reyes, Francisco J., Goddard, Lisa, Janicot, Serge, Arribas, Alberto, Lau, William, Colman, Andrew, Vellinga, M., Rowell, David P., Kucharski, Fred, Voldoire, Aurore
• Other Authors: Departamento de Fisica de la Tierra, Astronomía y Astrofísica Madrid, Universidad Complutense de Madrid = Complutense University of Madrid Madrid (UCM), Instituto de Geociencias, Universidad Complutense de Madrid = Complutense University of Madrid Madrid (UCM)-Consejo Superior de Investigaciones Cientificas España = Spanish National Research Council Spain (CSIC), Department of Atmospheric and Oceanic Sciences Los Angeles (AOS), University of California Los Angeles (UCLA), University of California (UC)-University of California (UC), School of Environmental Sciences, University of Liverpool, Lamont-Doherty Earth Observatory (LDEO), Columbia University New York, Istituto di Biometeorologia Roma (IBIMET), National Research Council of Italy, Institut Català de Ciències del Clima, Department of Geological Sciences Austin, Jackson School of Geosciences (JSG), University of Texas at Austin Austin -University of Texas at Austin Austin, NCAS-Climate Reading, Department of Meteorology Reading, University of Reading (UOR)-University of Reading (UOR), Instituto de Ciencias Ambientales Toledo (ICAM), Universidad de Castilla-La Mancha = University of Castilla-La Mancha (UCLM), Center for Climate Systems Research New York (CCSR), Biogéosciences UMR 6282 (BGS), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, Institució Catalana de Recerca i Estudis Avançats = Catalan Institution for Research and Advanced Studies (ICREA), International Research Institute for Climate and Society (IRI), Earth Institute at Columbia University, Columbia University New York -Columbia University New York, Processus de la variabilité climatique tropicale et impacts (PARVATI), 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)-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)-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), Met Office Hadley Centre (MOHC), United Kingdom Met Office Exeter, GSFC Laboratory for Atmospheres, NASA Goddard Space Flight Center (GSFC), Abdus Salam International Centre for Theoretical Physics Trieste (ICTP), 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), This work was supported by Spanish projectsMINECO CGL2011-13564-E and GL2012-38923-C02-01. Support from the U.S. National Science Foundation(Awards SES-1048946, ATM-1036604, AGS-1041477,and AGS-1115506) is gratefully acknowledged. Alsogratefully acknowledged are theGCMmodeling groups,the Program for Climate Model Diagnosis and Intercomparison(PCMDI), and the World Climate ResearchProgramme’s Working Group on CoupledModeling (WGCM) for their roles in making availablethe WCRP CMIP5 multimodel dataset. Support of thisdataset is provided by the Office of Science, U.S. Departmentof Energy (DOE). We acknowledge the EUQWECI, PREFACE, and SPECS projects both fundedby the European Commission’s Seventh FrameworkResearch Programme under Grant Agreements 243964,603521, and 308378 respectively. Based on a Frenchinitiative, AMMA was built by an international scientificgroup and is currently funded by a large numberof agencies, especially from France, the United Kingdom,the United States, and Africa. It has been thebeneficiary of a major financial contribution from theEuropean Community’s Sixth Framework ResearchProgramme.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; North Atlantic
• Online Access: https://hal.science/hal-01228751; https://hal.science/hal-01228751/document; https://hal.science/hal-01228751/file/%5B15200442%20-%20Journal%20of%20Climate%5D%20Variability%20and%20Predictability%20of%20West%20African%20Droughts%20A%20Review%20on%20the%20Role%20of%20Sea%20Surface%20Temperature%20Anomalies.pdf; https://doi.org/10.1175/JCLI-D-14-00130.1

27 pages International audience The Sahel experienced a severe drought during the 1970s and 1980s after wet periods in the 1950s and 1960s. Although rainfall partiallyrecovered since the 1990s, the drought had devastating impacts on society. Most studies agree that this dry period resulted primarily fromremote effects of sea surface temperature (SST) anomalies amplified by local land surface–atmosphere interactions. This paper reviewsadvances made during the last decade to better understand the impact of global SST variability on West African rainfall at interannual todecadal time scales. At interannual time scales, a warming of the equatorial Atlantic and Pacific/Indian Oceans results in rainfall reductionover the Sahel, and positive SST anomalies over the Mediterranean Sea tend to be associated with increased rainfall. At decadal timescales, warming over the tropics leads to drought over the Sahel, whereas warming over the North Atlantic promotes increased rainfall.Prediction systems have evolved from seasonal to decadal forecasting. The agreement among future projections has improved fromCMIP3 to CMIP5, with a general tendency for slightly wetter conditions over the central part of the Sahel, drier conditions over thewestern part, and a delay in the monsoon onset. The role of the Indian Ocean, the stationarity of teleconnections, the determination of theleader ocean basin in driving decadal variability, the anthropogenic role, the reduction of the model rainfall spread, and the improvement ofsome model components are among the most important remaining questions that continue to be the focus of current international projects.