Abstract
The empirical typhoon models or the advanced mesoscale meteorological models are often used to calculate wind and pressure fields as external forces of storm surge simulations. The conventional typhoon models can calculate wind field of a virtual typhoon with low computational cost. However, the typhoon models do not include the influences of the land topography. On the other hand, the advanced mesoscale meteorological models can calculate highly accurate wind field with considering the geographical features, while it requires huge computational cost and is difficult to simulate virtual typhoons. The aim of this study is to propose a correction method of wind field obtained by a conventional typhoon model using correction coefficients based on the wind field by an advanced mesoscale meteorological model. First, wind fields were simulated with both the conventional typhoon model and the advanced mesoscale meteorological model under the same typhoon conditions. Then, comparing the both numerical results, the correction coefficients were determined by the least-square method for each grid of computational mesh depending on the wind speed and direction (octas). In addition, storm surge simulations were performed using a coastal circulation model to investigate the effect of the correction of wind field.
The wind speed is affected by the influence of the geographical feature like the advanced mesoscale meteorological model. In the time series of the corrected wind speed during typhoon, both the maximum wind speed and its occurance time it occurs agree well with the result of the advanced mesoscale meteorological model. Furthermore, the result of the storm surge estimation is improved by the proposed correction method. The results indicate that the correction method is valuable for getting the wind field data with accuracy and low computational cost.
