1. Evapotranspiration trends and variability in southeastern South America: The roles of land‐cover change and precipitation variability
- Author
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Ruscica, Romina, Sörensson, Anna, Diaz, Leandro, Vera, Carolina, Castro, Aline, Papastefanou, Phillip, Rammig, Anja, Rezende, Luiz, Sakschewski, Boris, Thonicke, Kirsten, Viovy, Nicolas, Randow, Celso, Universidad de Buenos Aires [Buenos Aires] (UBA), National Institute for Space Research [Sao José dos Campos] (INPE), Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), Potsdam Institute for Climate Impact Research (PIK), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), CLIMAX Project was funded by Belmont Forum/ANR-15-JCL/-0002-01, BMBF FKZ 01LP1610A, and FAPESP-BELMONT-Process 2015/50687-8, Agencia Nacional dePromoci on Científica y Tecnol ogica (ANPCyT), Argen-tina [PICTs 2017-1406, 2018-02511], University of BuenosAires, Argentina [UBACyT20020170100428BA], SÃOPAULO STATE RESEARCH FOUNDATION [grants2015/50687-8 and 2017/03048-5] and National Councilfor Scientific and Technological Development [301084/2020-3]. ORCHIDEE simulations were performed usingHPC resources from GENCI-TGCC [2018-6328], and ANR-15-JCLI-0002,CLIMAX,Climate Services Through Knowledge Co-Production: A Euro-South American Initiative For Strengthening Societal Adaptation Response to Extreme Events(2015)
- Subjects
Vegetation models ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,Precipitation variability ,Evapotranspiration ,Land-cover changes ,Trends analysis ,Dipole evolution ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,South America climate - Abstract
International audience; Southeastern South America is subject to considerable precipitation variability on seasonal to decadal timescales and has undergone very heavy land-cover changes (LCCs) since the middle of the past century. The influence of local LCC and precipitation as drivers of regional evapotranspiration (ET) long-term trends and variability remains largely unknown in the region. Here, ensembles of stand-alone dynamic global vegetation models (DGVMs) with different atmospheric forcings are used to disentangle the influence of those two drivers on austral summer ET from 1950 to 2010. This paper examines the influence of both the El Niño-Southern Oscillation (ENSO) and the dipole-like first-mode of southeastern South American precipitation variability (EOF1) on regional ET. We found that in the lower La Plata Basin, ET was driven by precipitation variability and showed a positive summer trend. Moreover, the region showed marked seasonal anomalies during El Niño and La Niña summers but mainly during EOF1 phases. On the contrary, in the upper La Plata Basin, LCCs forced the negative summer ET trend and particularly reduced the summer anomalies of the late 1990s, a period of ENSO and EOF1-positive phases. In the South Atlantic Convergence Zone region, the high ET uncertainty across ensemble members impeded finding robust results, which highlights the importance of using multiple DGVMs and atmospheric forcings instead of relying on single model/forcing results.
- Published
- 2022