Sea surface temperature anomalies in the Gulf of California

Satellite infrared images from January 1984 to December 2000 are used to describe interannual sea surface temperature (SST) anomalies in the Gulf of California. The predominant positive anomalies are due to El Ni o, especially in 1997-1998, with deviations of over 3°C from the seasonal climatology. The largest negative anomaly (~-4°C) was associated with La Ni a of 1988-89. The 1986-87 El Ni o had the weakest effect, with anomalies < 2 °C. The SST anomalies tend to be earlier and stronger in the region just south of the mid-gulf archipelago; this may be due to the presence of strong SST fronts in that area. Some anomalies appear to be connected to anomalies of the same sign in the Western Hemisphere Warm Pool of the eastern Pacific. Some anomalies, especially in the northern gulf, may be caused by local processes. The origin of some anomalies remain unknown. A statistically significant warming of ~ 1°C during the 17 years of the record was observed, apparently within the interdecadal variability of the Pacific ocean.