In this article, thirteen years of weekly sea surface temperature (SST) fields derived from NOAA Advanced Very High Resolution Radiometer global area coverage infrared satellite data, from January 1982 to December 1994, are used to investigate spatial and temporal variabilities of SST seasonal cycle in the Southwest Atlantic Oceano This work addresses large scale variations over the eastem South American continental shelf and slope regions limited offshore by the 1000-m isobath, between 42° and 22°S. SST time series are fit with annual and semi-annual harmonics to describe the annual variation of sea surface temperatures. The annual harmonic explains a large proportion of the SST variability. The coefficient of determination is highest (>; 90%) on the continental shelf, decreasing offshore. The estimated amplitude of the seasonal cycle ranges between 4° and 13°e throughout the study area, with minima in AugustSeptember and maxima in February-March. After the identification and removal of the dominant annual components ofSST variability, models such as the one presented here are an attractive tool to study interannual SST variability.
