Intraseasonal Drivers of the 2018 Drought Over São Paulo, Brazil

Frontiers in Climate

Caio A. S. Coelho¹  Natália Machado Crespo²  Anderson Augusto Bier²  Rosmeri Porfírio da Rocha²  Tércio Ambrizzi²  Anita Drumond²  Ana Carolina Nóbile Tomaziello²  Henri Rossi Pinheiro²  Paola Gimenes Bueno²  Maria de Souza Custodio⁴  Luiz Felippe Gozzo⁴  Camila Bertoletti Carpenedo⁵  Luana Albertani Pampuch⁶  Raíssa de Matos Pimentel⁶  Helber Barros Gomes⁷  Cassia Akemi Castro Kuki⁸  Michelle Simões Reboita⁹ 

[1] Center for Weather Forecast and Climate Studies (CPTEC), National Institute of Space Research (INPE), Cachoeira Paulista, Brazil;Departamento de Ciências Atmosféricas, Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, São Paulo, Brazil;Department of Environmental Engineering, Institute of Science and Technology (ICT), São Paulo State University (UNESP), São José dos Campos, Brazil;Department of Physics and Meteorology, School of Sciences, São Paulo State University (UNESP), Bauru, Brazil;Department of Soils and Agricultural Engineering, Federal University of Paraná, Curitiba, Brazil;Graduate Program in Natural Disasters, UNESP/CEMADEN, São José dos Campos, Brazil;Institute of Atmospheric Sciences, Federal University of Alagoas (UFAL), Maceió, Brazil;Institute of Electric Systems and Energy, Federal University of Itajubá (UNIFEI), Itajubá, Brazil;Institute of Natural Resources, Federal University of Itajubá (UNIFEI), Itajubá, Brazil;

关键词: drought;    SPI;    São Paulo;    intraseasonal oscillations;    teleconnection;   

DOI  :  10.3389/fclim.2022.852824

来源: DOAJ

【 摘 要 】

Dry conditions occurred over São Paulo state (southeastern Brazil) from February to July 2018, causing the driest semester in 35 years. Socioeconomic impacts included a record number of fire spots, most adverse conditions to pollutant dispersion in 3 years and the winter's lowest water reservoirs stored volume in 17 years. This paper discusses climate drivers to the onset and persistence of the dry conditions, with special attention to the intraseasonal forcing. Barotropic atmospheric circulations forced by the intraseasonal Pacific-South America teleconnection pattern, embedded in the lower frequency setup of the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation, were identified as main large-scale forcings to reduce precipitation. Drought evolution was modulated by other intraseasonal drivers such as the Madden Julian, Antarctic and 10–30 days Oscillations. A break in the 6-month dry condition, in March 2018, highlighted the important role of such oscillations in determining precipitation anomalies over SP. Results show that intraseasonal phenomena and their interactions control drought characteristics such as magnitude, persistence and spatial distribution within a setup determined by lower-frequency oscillations. The intraseasonal timescale seems to be key and must be considered for a complete description and understanding of the complex drought evolution process in São Paulo.

【 授权许可】

Unknown