Effect of the surface wind stress parameterization on the storm surge modeling

The wind stress over ocean is a crucial surface forcing in the storm surge modeling. This study investigates the effect of surface wind stress parameterizations and grid resolutions on the storm surge modeling. Three drag coefficient (Cd) formulas at high wind speeds have been tested for the Super Typhoon Maemi (2003) using the grid resolution of 1/12°, 1/60°, and 1/360°: (i) the linearly-increasing Cd by Wu [Wu, J., 1982. Wind-stress coefficients over sea surface from breeze to hurricane. J. Geophys. Res. 87, 9704--9706], (ii) the fast-increasing Cd by the WAVEWATCH III (WW3) model, and (iii) the leveling-off Cd by the coupled wind–wave (CWW) model. Experimental results show that a higher resolution model that has a better resolution of complex topography and the coastline produces higher surge, on the average. In particular, when the grid resolution of the storm surge model is greatly improved, the CWW model with the leveling-off Cd at high winds shows the best performance in the surge simulation, while both WW3 and Wu models with unrealistic high Cd at high winds tend to produce an overestimated surge.