Development of a physics-ecosystem coupled model and its applicability to the one-dimensional ecosystem at the Korea Strait

Abstract

A physics-ecosystem coupled model was developed to study the marine ecosystem around the Korean Peninsula. The physics module of the developed model uses finite difference grid in the horizontal coordinates(C-grid). And it uses a mixed σ-z grid in the vertical coordinates to describe realistically the shallow and mild slope topography along with the deep and steep slope topography. The ecosystem module, which is 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, and it comprises bottom detrital sediment also.In order to test the model performance, the one-dimensional model was applied to the Korea Strait and the model results were compared with the observed time series data of the whole water column of the M1 station at the Korea Strait. The reproduced results, to a certain degree, show good agreement with the observed ones and similar pattern of seasonal variation. In seasonal variations of phytoplankton, diatoms show strong and short spring bloom only. Flagellates show weak and long fall/winter bloom as well as strong and short spring bloom. Blue-green algae show weak summer bloom at the surface initially and then disappear soon. The model results, however, give shallower mixed layer depth than the observed one, grid in the vertical coordinates to describe realistically the shallow and mild slope topography along with the deep and steep slope topography. The ecosystem module, which is 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, and it comprises bottom detrital sediment also.In order to test the model performance, the one-dimensional model was applied to the Korea Strait and the model results were compared with the observed time series data of the whole water column of the M1 station at the Korea Strait. The reproduced results, to a certain degree, show good agreement with the observed ones and similar pattern of seasonal variation. In seasonal variations of phytoplankton, diatoms show strong and short spring bloom only. Flagellates show weak and long fall/winter bloom as well as strong and short spring bloom. Blue-green algae show weak summer bloom at the surface initially and then disappear soon. The model results, however, give shallower mixed layer depth than the observed one,