Kilpatrick, T., S.-P. Xie, A. J. Miller and N. Schneider, 2018:

Satellite observations of enhanced chlorophyll variability in the Southern California Bight


Journal of Geophysical Research-Oceans, sub judice.

Abstract. Satellite observations from the Moderate-resolution Imaging Spectroradiometer (MODIS) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS) reveal a “tongue” of elevated near-surface chlorophyll that extends into the Southern California Bight from Point Conception. A local chlorophyll maximum at the western edge of the bight, near the Santa Rosa Ridge, indicates that the chlorophyll is not simply advected from Point Conception, but is enhanced by local upwelling. Chlorophyll in the bight peaks in May and June, in phase with the seasonal cycle of wind stress curl. The spatial structure and seasonal variability suggest that the local chlorophyll maximum is due to a combination of bathymetric influence from the Santa Rosa Ridge, and orographic influence from the coastline bend at Point Conception, which causes sharp wind stress curl in the bight. High-resolution glider observations show thermocline doming in May-June, in support of the local upwelling effect.
Covariability between chlorophyll, surface wind stress, and SST indicates that non-seasonal chlorophyll variability in the bight is closely related to SST, but the spatial patterns of SST influence vary by time scale: sub-annual chlorophyll variability is linked to local wind-forced upwelling, while interannual chlorophyll variability is linked to large-scale SST variations over the northeast Pacific. This suggests a greater role for nonlocal processes in the bight’s low-frequency chlorophyll variability.

Preprint (pdf)