Circulation Patterns and Associated Rainfall Over South Tropical South America: GCMs Evaluation During the Dry‐To‐Wet Transition Season

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Olmo, M., Espinoza, J.‐c., Bettolli, M., Sierra, J. P., Junquas, C., Arias, P., Moron, Vincent, Balmaceda-Huarte, R.
• Other Authors: Universidad de Buenos Aires Buenos Aires (UBA), Instituto Franco-Argentino sobre Estudios de Clima y sus Impactos Buenos Aires (IFAECI), Centro de Investigaciones del Mar y la Atmósfera (CIMA), Consejo Nacional de Investigaciones Científicas y Técnicas Buenos Aires (CONICET)-Facultad de Ciencias Exactas y Naturales Buenos Aires (FCEyN), Universidad de Buenos Aires Buenos Aires (UBA)-Universidad de Buenos Aires Buenos Aires (UBA)-Consejo Nacional de Investigaciones Científicas y Técnicas Buenos Aires (CONICET)-Facultad de Ciencias Exactas y Naturales Buenos Aires (FCEyN), Universidad de Buenos Aires Buenos Aires (UBA)-Universidad de Buenos Aires Buenos Aires (UBA)-Centre National de la Recherche Scientifique (CNRS), Consejo Nacional de Investigaciones Científicas y Técnicas Buenos Aires (CONICET), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Universidad de Antioquia = University of Antioquia Medellín, Colombia, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Lamont-Doherty Earth Observatory (LDEO), Columbia University New York
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; Austral; Espinoza; South Atlantic Ocean
• Online Access: https://hal-cnrs.archives-ouvertes.fr/hal-03766913; https://hal-cnrs.archives-ouvertes.fr/hal-03766913/document; https://hal-cnrs.archives-ouvertes.fr/hal-03766913/file/JGR%20Atmospheres%20-%202022%20-%20Olmo%20-%20Circulation%20Patter_220614_100619.pdf; https://doi.org/10.1029/2022JD036468

International audience South Tropical South America (STSA), extended approximately between 10°N-30°S and 90°W-30°W, is a wide region where diverse interactions among biomass, land surface processes and atmospheric convection take place. These interactions modulate the local and regional climate and directly impact on the socio-environmental activities (Fu et al., 2013; Reis et al., 2018; Zhang et al., 2015). STSA hosts the Amazonia-the world's largest rainforest and one of the major sources of evapotranspiration-playing a critical role in the global balances of energy, water, moisture and carbon (Gatti et al., 2021; Llopart et al., 2020). The region presents unique biodiversity and geographical patterns, mainly due to the interaction of the Amazonia and the Andes mountain range, which have deep implications in the atmospheric dynamics, moisture transport and river discharge not only throughout STSA but also in remote regions of the continent (Arias, Garreaud, et al., 2021; Espinoza et al., 2020; Sierra et al., 2021). Precipitation (PP) over STSA presents a marked spatio-temporal variability, strongly controlled by the South American Monsoon System (SAMS), with rainfall maxima during its active phase during the austral summer (Marengo et al., 2012; Vera et al., 2006). The monsoonal circulation-which develops in response to seasonal changes in thermal land-sea contrasts-is connected to different documented atmospheric features, including a NW-SE band of convergence and convective activity over the southeast of South America and the adjacent South Atlantic ocean known as the South Atlantic Convergence Zone (SACZ), an anticyclonic center located