A Study of Sea Level Variations and Currents off Baja California

Abstract

Sea level data are used to estimate the average surface current between Guadalupe Island and the coast of Baja California. The procedure is to 1) eliminate frequencies higher than one cycle per day by filtering sea level data from Guadalupe Island and a coastal station, 2) level between sea level stations with hydrographic data, and 3) compute currents using the geostrophic approximation. The resulting records of currents for the three periods of operation of the Guadalupe station show three time scales of events: seasonal, 5–7 days and 15–30 days. The 5–7 day oscillations are believed to be generated by local winds. However, the 15–30 day events, which are largest in amplitude, have no counterpart in local weather. It is speculated that they result from forcing of a whole-ocean scale.