Adjoint Assimilation of SeaWiFS data into a Marine Ecosystem Dynamical Model of the Bohai Sea and the North Yellow Sea

AbstractA three-dimensional coupled physical-biological model involving variational adjoint assimilation was applied to the Bohai Sea and the North Yellow Sea (BNYS), utilizing real chlorophyll data from the Sea-Viewing Wide Field-of-view Sensor (SeaWiFS). The coupled model consists of a simple three-dimensional Nutrient-Phytoplankton-Zooplankton-Detritus (NPZD) model and a primitive-equation physical model. There are 12 ecological parameters in the NPZD model. All these parameters are assumed to be time-varying. By using the data assimilation technique, the optimal values of these parameter were estimated, and the seasonal variabilities of these parameters were reconstructed. We find that some parameters are highly correlated, and they may have some internal relations. The time variances of most parameters seem reasonable. And the annual cycles of the estimated parameters may help us to improve the performance of the model. The comparison between simulation and observation shows that after assimilation of SeaWiFS data the output of the NPZD model agrees better with the observation