Development of a physics-ecosystem coupled model and its application to the Yellow and East China Sea

Abstract

A physics-ecosystem coupled model was developed and applied to the Yellow and East China Sea domain in order to reproduce the seasonal and inter-annual variability of the Yellow Sea ecosystem. The physics module of the model uses finite difference grid in the horizontal and a mixed σ-z grid in the vertical coordinates to describe realistically the shallow and mild slope topography of the Yellow Sea along with the deep and steep slope topography in the outskirts of the East China Sea. The ecosystem module, which is developed based on the ERGOM of Neumann(2000), is composed of nine functional groups, that is, three nutrients (nitrates, ammonia and phosphates), three phytoplankton (diatoms, flagellates and blue-green algae), one bulk-zooplankton, detritus and dissolved oxygen. The physics model was forced by six-hourly wind, pressure, SST and total cloud cover of ECMWF ERA-interim data at the sea surface and also forced by monthly elevation, depth-averaged velocity, layer velocity of HYCOM model results and monthly temperature and salinity of WOA09 at the open boundary points, together with the interpolated tidal constants from TPXO8. Monthly nitrates, phosphates and oxygen from WOA09 were imposed at the open boundary of the ecosystem module. To begin with, one-dimensional model test results are compared with the observed time series of M1 station at the Korea Strait and it shows, to some degree, similar pattern of seaference grid in the horizontal and a mixed σ-z grid in the vertical coordinates to describe realistically the shallow and mild slope topography of the Yellow Sea along with the deep and steep slope topography in the outskirts of the East China Sea. The ecosystem module, which is developed based on the ERGOM of Neumann(2000), is composed of nine functional groups, that is, three nutrients (nitrates, ammonia and phosphates), three phytoplankton (diatoms, flagellates and blue-green algae), one bulk-zooplankton, detritus and dissolved oxygen. The physics model was forced by six-hourly wind, pressure, SST and total cloud cover of ECMWF ERA-interim data at the sea surface and also forced by monthly elevation, depth-averaged velocity, layer velocity of HYCOM model results and monthly temperature and salinity of WOA09 at the open boundary points, together with the interpolated tidal constants from TPXO8. Monthly nitrates, phosphates and oxygen from WOA09 were imposed at the open boundary of the ecosystem module. To begin with, one-dimensional model test results are compared with the observed time series of M1 station at the Korea Strait and it shows, to some degree, similar pattern of sea