SEASONALITY OF CHLOROPHYLL CONCENTRATIONS IN THE CALIFORNIA CURRENT -A COMPARISON OF 2 METHODS

We have compared estimates of seasonal variations in chlorophyll conce ntrations in the California Current as derived from a large series of in situ, water-column, measures and from the Coastal Zone Color Scanne r-West Coast Time Series (WCTS) in both original and corrected forms. We find substantial differences between the two methods, satellite and in situ. The original WCTS showed winter to be the peak season for pi gment concentration everywhere, but the in situ data did not. A previo us study of the corrected WCTS data found ''a strong seasonal cycle wi th a spring summer maximum,'' but the in situ data contained no convin cing evidence for a ''strong'' cycle when all of the data were examine d. Some individual years (e.g., 1984) do have dear spring maxima, part icularly very near shore, but most do not. There are extensive interan nual variations. The overall relation between surface in situ (or 0-20 m) pigment concentrations and integrated, in situ water-column (0-150 m) concentrations is very uncertain in terms of mean concentrations p er unit volume, spatial heterogeneity, and temporal change.