Connection between sea surface temperature patterns and low level geopotential height in the South Atlantic Ocean

Abstract

The aim of this work is to study the connection between sea surface temperature (SST) in the South Atlantic Ocean and the semi-permanent anticyclone. In order to do this, SST and geopotential height in 1000 hPa from the NCEP/NCAR reanalysis for the 1981-2016 period were used, with a spatial resolution of 2.5o × 2.5o and restricted to the domain 65o W-20o E, 50o S-0o to study the South Atlantic Ocean. Variability modes of the seasonal anomalies of both variables were calculated using the T mode of principal component analysis. In addition, to study the connection between both variables, the linear correlation between the temporal series of the eigenvectors of the different principal components of SST and geopotential height in 1000 hPa were calculated. Results showed that both in summer and spring, negative geopotential height anomalies to the south are associated with warmer SSTs in the central and north regions of the South Atlantic Ocean and cooler to the south. However, in autumn and winter, a lower than normal geopotential height in the southwestern region is connected to warmer SST anomalies in the south area and cooler in the center of the basin.