@InProceedings{EidtCava:2018:RaVaOv,
author = "Eidt, Renata Tatsch and Cavalcanti, Iracema Fonseca de
Albuquerque",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto
Nacional de Pesquisas Espaciais (INPE)}",
title = "Rainfall variability over South America associated with SST
anomalies in South Pacific and South Atlantic oceans",
year = "2018",
organization = "International Conference for Southern Hemisphere Meteorology and
Oceanography, 12. (AMOS-ICSHMO)",
abstract = "Sea surface temperature (SST) anomalies influence atmospheric
circulation and contribute to changes in weather and climate
around the globe. It is already known that precipitation over
continental areas can be associated with SST variability in the
tropics. However, the importance of extratropical oceans is still
not completely understood. The aim of this study is to investigate
the influence of extratropical SST anomalies to rainfall
variability, focusing on South America, and the oceanic and
atmospheric processes involved. The period from 1981 to 2010 was
studied in a monthly scale, using SST and precipitation data
obtained from NOAA datasets (ERSST-v5 and GPCP, respectively), and
atmospheric data from CFSR reanalysis. Singular Value
Decomposition (SVD) showed connectivity between SST variations in
extratropical oceans and rainfall variability over southeastern
South America, an important agricultural area. Extreme wet and dry
events over this region were identified using the Standardized
Precipitation Index (SPI), to a further evaluation of the oceanic
conditions associated with these episodes. Empirical Orthogonal
Functions (EOF) and SVD were applied for the identification of
principal modes of variability. Dipoles of SST were identified in
South Pacific and South Atlantic oceans. Two areas of opposite
signs were observed in western (~25°S) and southern (~55°S) South
Pacific Ocean, regions of atmospheric blocking and the South
Pacific Convergence Zone (SPCZ). Positive SST anomalies in the
southern area are related to precipitation increase over
southeastern South America. The southern oceanic area is also
associated with a dipole of precipitation over Southeast Asia and
central Pacific Ocean. A dipole signal was also noticed in western
South Atlantic Ocean, mainly from September to December, varying
in position and intensity near South America. The results obtained
showed that extratropical oceans have an important role for
precipitation variability in remote regions, and the oceanic areas
identified can contribute to climate monitoring.",
conference-location = "Sydney, Australias",
conference-year = "05-09 feb.",
language = "en",
urlaccessdate = "28 abr. 2024"
}