ASSIMILATION OF BIO-OPTICAL PROPERTIES INTO COUPLED PHYSICAL, BIO-OPTICAL COASTAL MODEL

Data assimilation experiments with the coupled physical, bio-optical model of Monterey Bay are presented. The approach is based on the representation of the error covariances in the subspace of the multivariate (bio-optical, physical) empirical orthogonal functions (EOFs) estimated from the model run. Estimated coupled bio-optical, physical error covariances are used in the Kalman gain update providing updates of coupled bio-optical properties in accord with the model dynamics and available observations. With the assimilation of satellite-derived bio-optical properties (chlorophyll-a and absorption due to phytoplankton), the model was able to reproduce intensity and tendencies in subsurface chlorophyll distributions observed at water samples locations in the Monterey Bay, CA. Data assimilation also improved agreement between the observed and model-predicted ratios between diatoms and small phytoplankton populations.