摘要
The Amazon basin has experienced an extreme drought that started in the austral summer of 2022-23 and extends into 2024. This drought started earlier than other previous droughts. Although some rain fell during the austral summer, totals remained below average. Higher temperatures during austral winter and spring 2023, which affected most of Central South America, then aggravated drought conditions. This coincided with an intense El Niño and abnormally warm tropical North Atlantic Ocean temperatures since mid-2023. Decreased rainfall across the Amazon basin, negative anomalies in evapotranspiration (derived from latent heat) and soil moisture indicators, as well as increased temperatures during the dry-to-wet transition season, September-October-November (SON) 2023, combined to delay the onset of the wet season in the hydrological year 2023-24 by nearly two months and caused it to be uncharacteristically weak. SON 2023 registered a precipitation deficit of the order of 50 to 100 mm/month, and temperatures +3˚C higher than usual in Amazonia, leading to reduced evapotranspiration and soil moisture indicators. These processes, in turn, determined an exceptionally late onset and a lengthening of the dry season, affecting the 2023-2024 hydrological year. These changes were aggravated by a heat wave from June to December 2023. Drought-heat compound events and their consequences are the most critical natural threats to society. River levels reached record lows, or dried up completely, affecting Amazonian ecosystems. Increased risk of wildfires is another concern exacerbated by these conditions.
The Amazon basin has experienced an extreme drought that started in the austral summer of 2022-23 and extends into 2024. This drought started earlier than other previous droughts. Although some rain fell during the austral summer, totals remained below average. Higher temperatures during austral winter and spring 2023, which affected most of Central South America, then aggravated drought conditions. This coincided with an intense El Niño and abnormally warm tropical North Atlantic Ocean temperatures since mid-2023. Decreased rainfall across the Amazon basin, negative anomalies in evapotranspiration (derived from latent heat) and soil moisture indicators, as well as increased temperatures during the dry-to-wet transition season, September-October-November (SON) 2023, combined to delay the onset of the wet season in the hydrological year 2023-24 by nearly two months and caused it to be uncharacteristically weak. SON 2023 registered a precipitation deficit of the order of 50 to 100 mm/month, and temperatures +3˚C higher than usual in Amazonia, leading to reduced evapotranspiration and soil moisture indicators. These processes, in turn, determined an exceptionally late onset and a lengthening of the dry season, affecting the 2023-2024 hydrological year. These changes were aggravated by a heat wave from June to December 2023. Drought-heat compound events and their consequences are the most critical natural threats to society. River levels reached record lows, or dried up completely, affecting Amazonian ecosystems. Increased risk of wildfires is another concern exacerbated by these conditions.
作者
Jose A. Marengo
Ana P. Cunha
Jhan-Carlo Espinoza
Rong Fu
Jochen Schöngart
Juan C. Jimenez
Mabel C. Costa
Joao M. Ribeiro
Sly Wongchuig
Siyu Zhao
Jose A. Marengo;Ana P. Cunha;Jhan-Carlo Espinoza;Rong Fu;Jochen Schöngart;Juan C. Jimenez;Mabel C. Costa;Joao M. Ribeiro;Sly Wongchuig;Siyu Zhao(National Center for Monitoring and Early Warning of Natural Disasters/CEMADEN, So Jos dos Campos, Brazil;UNESP/CEMADEN, So Jos dos Campos, Brazil;Graduate School of International Studies, Korea University, Seoul, South Korea;Institut des Gosciences de lEnvironnement (IGE), Institut de Recherche pour le Dvelopement (IRD), Saint Martin dHeres, France;Instituto de Investigacin sobre la Enseanza de las Matemticas (IREM PUCP), Pontificia Universidad Catlica del Per, Lima, Peru;Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, Los Angeles, CA, USA;Departament of Environmental Dynamics, Instituto Nacional de Pesquisas da Amaznia (INPA), Manaus, Brazil;Global Change Unit (GCU) of the Image Processing Laboratory (IPL), Universitat de Valncia Estudi General (UVEG), Paterna, Spain;Laboratoire dEtudes en Gophysique et Ocanographie Spatiales (LEGOS), Universit de Toulouse, CNES/CNRS/IRD/UT3, Toulouse, France)
