Seasonal variability of the Northwestern Pacific Marginal Seas. Part II. Lower trophic ecosystem simulation results

Abstract

To understand and cope with those marine environmental pressures or stresses to marine ecosystem, it is necessary to assess the current statuses and their sensitivity to the changing parameters. Though the sophisticated marine ecosystem model is an indispensable tool for the assessment and prediction, it is still effort demanding challenge even though little attention has been paid in this region. In this study, a coupled 3D model system based on the POLCOMS (Proudman Oceanographic Laboratory Coastal Ocean Modelling System) ocean circulation model and the ERSEM (European Regional Seas Ecosystem Model) biogeochemical model has been applied as an initial attempt for the simulation in the northwestern Pacific marginal seas. The seasonal cycle of ecological state variables are extracted from the past 10 year simulation from 1992 to 2001 and the variability has been analyzed for the integrated amount within the mixed layer. As a measure of the model capability to catch seasonal changes, correlation coefficient (R2) and the cost function (CF) are introduced for nutrients and chlorophyll-a. For the calculation of these variables, monthly climatology of SeaWiFS chlorophyll-a over the period of 1998 to 2001 and the WOA09 (World Ocean Atlas 2009) nutrients (nitrate, phosphate and silicate) data have been used for comparisons.el is an indispensable tool for the assessment and prediction, it is still effort demanding challenge even though little attention has been paid in this region. In this study, a coupled 3D model system based on the POLCOMS (Proudman Oceanographic Laboratory Coastal Ocean Modelling System) ocean circulation model and the ERSEM (European Regional Seas Ecosystem Model) biogeochemical model has been applied as an initial attempt for the simulation in the northwestern Pacific marginal seas. The seasonal cycle of ecological state variables are extracted from the past 10 year simulation from 1992 to 2001 and the variability has been analyzed for the integrated amount within the mixed layer. As a measure of the model capability to catch seasonal changes, correlation coefficient (R2) and the cost function (CF) are introduced for nutrients and chlorophyll-a. For the calculation of these variables, monthly climatology of SeaWiFS chlorophyll-a over the period of 1998 to 2001 and the WOA09 (World Ocean Atlas 2009) nutrients (nitrate, phosphate and silicate) data have been used for comparisons.