운용해양 모델로서의 ROMS 적정성 평가 및 경기만 잔차류 변동성 연구

Abstract

Recent advances in ocean modeling and assimilation of observed data are subjects of intense research for operational forecast and hindcast analysis. In the present study, an overview of modeling frame using ROMS version 3.0 will be presented. The emphasis will be on the necessary modules for the operational system including two-way coupling between WRF, SWAN and topography change through MCT or ESMF library, nesting in three types (grid refinement, mosaic grids and composed grids), and data assimilation using 4DVAR through adjoint model analysis, etc. The ROMS v.3.0 has been implemented for the hindcast analysis of residual circulation in Kyunggi Bay with dry/wet scheme on the high-resolution grids. The residual current, defined as the flow averaged over the tidal cycle, plays an important role in estuarine and coastal processes. The macro-tidal river environment, the Great Han Estuary has three main channels through which the riverine sediment load is discharged into the Kyunggi Bay. It is generally accepted that the magnitude and direction of the residual current at each channel would determine the dispersal and deposition processes in the macro-tidal flats of varying composition of grain size. However up until now, it is far from clear whether the residual flows in this area are flood-dominant or ebb-dominant. There are numerous factors for the residual flows to be created and modified. In estuarine and coastal environment such as the Kyunggi Bay, the shallow water depth, interaction among multiple tidal constituents, river discharge and surface wind and wave effects would be the factors among others. The present study investigates the characteristics and variability of the residual flows at major points of the channels. We use two types of flow data; flow data measured in the field and the data simulated using the ROMS with dry and wetting nearshore module. One-month long current data have been used to estimate the residual currents using