Modulating Factors of the Climatological Variability of the Mexican Pacific; Model and Data.

Ana Laura Flores and Alejandro Pares-Sierra

CICESE, Ensenada, Mexico

The Sea Surface Temperature (SST) of the Mexican Pacific is examined in terms of the agents that modulate its variability. Twenty years
(1978-1997) of SST and wind data from the Comprehensive Ocean-Atmosphere Data Set (COADS), density climatological fields from LEVITUS and nine years (1993-2002) of sea surface height observations made by the TOPEX/Poseidon are used in this study. We found that the agents that drive the large scale variability can be grouped into remotely forced agents and local agents. For the large scale agents we identified the equatorial and coast Kelvin interannually propagating wave; advection of sea surface height westward around 10N, formed as instabilities in the North Equatorial Countercurrent (NECC) that is subsequently advected westward by the North Equatorial Current (NEC). And the Equator Current System position modulated by the Intertropical Convergence Zone (ITZC) position. As local agents we identified, the Gulf of California and the Gulf of Tehuantepec influence and the upwelling offshore Cabo Corrientes, Baja California and the Gulf of Tehuantepec ROMS was implemented for the Mexican Pacific and validated using the observed data previously described. Comparison of both data sets are shown and discussed.