Two years of drought in Southeast Brazil have led to water shortages in São Paulo, the country's most populous city. We examine the observed drought during austral summers of 2013/2014 and 2014/2015 and the related large-scale dynamics. The 2013-2014 precipitation deficits were more concentrated in the state of São Paulo, while in 2014-2015 moderate deficits were seen throughout the region. We find that a persistent warm sea surface temperature (SST) anomaly in the western tropical Pacific Ocean was an important driver of drought via atmospheric teleconnection in the two December-February seasons. The warm SST and associated convective heating initiated a wave train across the South Pacific. The resulting anticyclonic geopotential height anomaly over the southwest Atlantic expanded the westward margin of the South Atlantic high and prevented low-pressure systems from entering southeast Brazil from midlatitudes. This mechanism suggests a hemispheric symmetry to that proposed for the recent California drought.
DOI:
https://doi.org/10.1002/2015GL066314Skor altmetrik:
Jumlah Kutipan Dimensi:
Tahun publikasi
2015
Penulis
Seth, A.; Fernandes, K.; Camargo, S.J.
Bahasa
English
Kata kunci
drought
Geografis
Brazil
