Satellite measurements of chlorophyll distribution during spring 2005 in the California Current

Eight years of satellite data quantify spring 2005 surface chlorophyll-a (chl-a) anomalies in coastal areas of the California Current. Negative anomalies < - 1.0 mg m(-3) begin in March north of similar to 47 degrees N, spread south to 43 degrees N in April and 40 degrees N in May and June 2005, maximum (< - 2.0 mg m(-3)) north of 45 degrees N. Positive chlorophyll anomalies dominate from similar to 40 degrees N to 27 degrees N during this period. Strongest negative wind stress and positive coastal surface temperature anomalies are located south of maximum chl-a anomalies, in the region of maximum climatological summer wind stress. Despite the magnitude of these wind anomalies, they remain upwelling-favorable and negative chl-a anomalies are in higher latitude regions of weaker wind anomalies, sufficient however, to prolong winter downwelling, delaying the onset of spring upwelling. In June, winds across the entire region become strongly upwelling favorable and by July, chl-a anomalies switch to positive.