Sea surface temperature (SST) is shown to be an important key player to the studying of air-sea interaction phenomenon and in the determination of the regional and global climate variability. Recently, the Southern Annular Mode (SAM) has been recognized as one the most important modes of variability in the Southern Hemisphere, acting on different time scales which varies from the intraseasonal to the interannual variability. SAM is characterized by a modification in the atmospheric circulation pattern between high and mid latitudes, which modifies the meridional position of the western winds. Therefore, the objective of the present work is to investigate the influence of SAM over the SST in the southwestern Atlantic Ocean (SWAO) (18 \ub0S 58 \ub0S, 18 \ub0W 70 \ub0W), by means of computing the correlation between SST anomalies and the SAM index. Nine years of daily SST images from the Pathfinder best SST, with a spatial resolution of 9 x 9 km and encompassing the period of January 1993 to December 2001 have been used. SST anomalies (SSTA) were extracted after the removal of the annual and semi-annual components of the seasonal cycle of the original dataset. Correlation between the SAM index and SSTA was calculated for each grid point and used to construct a synthetic map of the spatial correlation. Correlation indices vary from -0.3 to 0.5 for most of the area of study. High positive values were observed over the Argentinean continental shelf between 36 e 56 \ub0S, whereas high negative values occurred in the offshore region between 18 e 32 \ub0S. Investigation of a potential relationship between the largest negative values of correlation observed over the continental shelf off Argentina and the wind components was also addressed. The wind product is derived from QuickScat, with a spatial resolution of 0.25 x 0.25 degrees and covering the period of January 1999 to December 2004. Correlation indices vary from -0.5 to 0.5 for the SWAO, but the largest positive correlation values were observed in the offshore region between 18 e 32 \ub0S and latitudes higher than 52 \ub0S, whereas the largest negative values took place in the offshore region between 36 e 48 \ub0S. Opposite to what was expected, the correlation was not significant over the Argentinean continental shelf, which, in turn, suggests that other physical processes should be driven the variability in this region. Our results suggest that the SAM index influences and contributes to the SSTA behavior in the SWAO, although this variability may be caused by other physical mechanisms which deserve further investigation.Pages: 1427-143
