The Effect of Local Sea Surface Temperatures on Atmospheric Circulation over the Tropical Atlantic Sector

Abstract

The effects of tropical Atlantic sea surface temperature (SST) anomalies on atmospheric circulation are examined by analyzing several ensembles of integrations of an atmospheric general circulation model (AGCM) forced with differently configured SSTs. An attempt is made to separate the atmospheric response to local SST forcing from internal atmospheric variability, using various statistical analyses. The analyses reveal a robust pattern of atmospheric response to SST forcing. The dominant response is largely confined within the tropical Atlantic sector and may be associated with the variation in location and intensity of the intertropical convergence zone (ITCZ) in response to changes in SST gradient near the equator. Within the deep Tropics, particularly in the western tropical Atlantic warm pool region, there is an indication of a positive feedback between surface heat flux and SST anomalies. In this warm SST region, the latent heat flux tends to dominate surface heat flux variability, and the ... Abstract The effects of tropical Atlantic sea surface temperature (SST) anomalies on atmospheric circulation are examined by analyzing several ensembles of integrations of an atmospheric general circulation model (AGCM) forced with differently configured SSTs. An attempt is made to separate the atmospheric response to local SST forcing from internal atmospheric variability, using various statistical analyses. The analyses reveal a robust pattern of atmospheric response to SST forcing. The dominant response is largely confined within the tropical Atlantic sector and may be associated with the variation in location and intensity of the intertropical convergence zone (ITCZ) in response to changes in SST gradient near the equator. Within the deep Tropics, particularly in the western tropical Atlantic warm pool region, there is an indication of a positive feedback between surface heat flux and SST anomalies. In this warm SST region, the latent heat flux tends to dominate surface heat flux variability, and the ...