UC Santa Cruz

This thesis presents a descriptive analysis of chlorophyll, surface currents, and sea surface temperature within the Gulf of the Farallones, occupying regions of three NOAA National Marine Sanctuaries along the central California coast. The seasonal cycles of each are described from a 24-year chlorophyll-a record, 10-year record of surface currents, and 20-year SST record. EOF analysis of chlorophyll revealed four distinct modes of variability: a single-signed pattern, a north-south split, an onshore-offshore structure, and a three-way split in which the Gulf of the Farallones is opposite to the regions north, south, and seaward. Surface currents via HF Radar and SST are also characterized through EOF analysis, to ultimately investigate their relationship to chlorophyll. Both surface currents and SST are significantly correlated to said patterns in chlorophyll, with the strongest correlation being between the north-south split in chlorophyll and an alongshore current pattern. A 19-year time series of normalized water-leaving radiance at the 555 nm band (nLw555) is used to calculate and describe the seasonal cycle of the San Francisco Bay Plume, which is compared to that of chlorophyll. Monthly and daily anomalies in chlorophyll are both significantly positively correlated to the magnitude of the SF Bay plume. The ecological structure of the area of interest to this study is of considerable importance to understand, particularly in order to implement effective conservation and management strategies.