Chlorophyll variability in eastern boundary currents

Abstract

The first three years of SeaWiFS data (1997-2000) provide the most complete quantification to date of chlorophyll seasonal variability along the full latitudinal extent of the four major eastern boundary currents (EBCs). Comparisons to previously published chlorophyll seasonal climatologies deduced from the relatively sparse coverage provided by the Coastal Zone Color Scanner (CZCS) show significant differences in both southern hemisphere EBCs, while northern hemisphere regions are qualitatively similar. Comparisons between chlorophyll and cross-shelf Ekman transport seasonal cycles, calculated from coincident satellite scatterometer data, show seasonal maxima have similar phases over most of the California Current, at higher (> 32°S) latitudes in the Peru-Chile and Benguela Currents (> 30°S) and at lowest latitudes (< 20°N) in the Canary Current. Latitudinal zones within which phases diverge are indicative of alternate and/or more distant forcing.