Sensitivity of Simulated Circulation Dynamics to the Choice of Surface Wind Forcing in the Japan/East Sea

摘要

The circulation sensitivity to the choice of wind-forcing product is investigated with the NRL Layered Ocean Model (NLOM) configured for the Japan/East Sea. Monthly climatologies from seven different wind-stress data sets (and wind-stress curl) are formed from observed and model-derived atmospheric data Sets. The resulting maps of wind-stress curl reveal significantly different spatial patterns and magnitudes, even two with largely opposite large-scale patterns of wind-stress curl. These wind Sets were used in forcing three sets of Simulations, 1/8 degree linear and 1/8 degree and 1/32 degree nonlinear. All of the nonlinear simulations include the NB, which is mainly due to isopycnal outcropping. This creates another inflow to outflow pathway, diverting some of the flow from the East Korean Warm Current (EKWC) and allowing the wind-stress curl to compete better with Straits forcing in determining the EKWC separation latitude. A Series of six 1/32 degree simulations forced inter-annually with 6-hourly winds 1979-93 are used to separate the model variability due to wind forcing (deterministic) and flow instabilities (nondeterministic). This analysis indicates that flow instabilities are the dominant source of SSH variability over a large majority of the basin, especially near 37-38 degree N, where the EKWC separates from the coast, and forcing dominates the SSH variability in the coastal wave guide and over the deep basins and troughs.