Changes in the California current system observed off northern California during July-August 1986

Abstract

Changes in the flow pattern of the California Current System (CCS) in a relatively short time period (~ one week) are investigated. The offshore flow pattern changed orientation from southwestward to southward and a cool filament seen previously was no longer discernible. The nearshore flow pattern changed from a predominantly southward to a northward flow. The changes occurred between two OPTOMA cruises conducted in the summer of 1986. Two possible causes are investigated for these changes: 1) a change in the poleward undercurrent of the CCS, and 2) a change in the coastal winds. Analysis of cross-sections of the poleward undercurrent indicate that it remained subsurface throughout the cruises. Analysis of wind data indicate that southward winds were the dominant wind pattern throughout the first cruise. Wind data from a moored buoy off Point Arena indicate northward winds (i.e., wind reversals) following the first cruise, which could be associated with the changes in the flow patterns of the CCS.