Factors that modulate the seasonal variability of the sea surface temperature of the Eastern Tropical Pacific

Abstract

Seasonal variability of the sea surface temperature (SST) in the Eastern Tropical Pacific were studied. For this purpose the following data were analyzed: SST and wind data from the Comprehensive Ocean–Atmosphere Data Set from 1978 to 1997, temperature and salinity fields from the LEVITUS climatology and sea surfac heights from TOPEX/Poseidon from 1993 to 2002. Various locally important factors that modulate this variability were identified: (1) the influence of the Gulf of California with the seasonal variability of the California Current, which extend about 200 km from the mouth towards the south and west, and about 300 km from the peninsula's west side toward the north; (2) the influence of the Gulfs of Tehuantepec and Papagayo where, due to the behavior of the winds, a local cooling of the surface during winter is generated; (3) upwelling at the Equator, off Cabo Corrientes, and off the west coast of Baja California; (4) spatial and temporal variation of the Inter–Tropical Convergence Zone and its relation with the thermal equator; (5) remote propagating signals in the zone; and (6) seasonal variations of the Equatorial Current System.