Modeling the Response of Multi-scale Winds in a Mountainous Coastal Region to SST Changes over the East Sea in Korea

The effects of the Sea Surface Temperature (SST) changes on multi-scale winds (micro- and meso-scale) in a mountainous coastal region were quantitatively analyzed using Weather Research and Forecasting (WRF) model. The SST observations obtained from coastal buoys, ships and AVHRR/NOAA-17 were utilized to provide high-resolution distributions of SST for multiple domains. WRF simulations were compared in three different horizontal resolutions (1.0, 0.5 and 0.083 degree) of SST data to exam the sensitivity of meso-scale winds fields to SST changes. In addition, in order to understand the effects of the changed meso-scale winds due to the SST variations on micro-scale winds in a coastal urban area, an application of Computational Fluid Dynamics (CFD) model using the boundary wind fields generated by WRF was made in fine domain. The results showed that the SST variations can affect multi-scale wind fields over the mountainous coastal area: a small but appreciable change in winds was largely found along the coastal line for the simulation using high-resolution SST of 0.083 degree, especially inland near the shoreline where diurnal wind and temperature variations were markedly different from those of outer sea. Interestingly, the CFD simulation demonstrated that even small change in meso-scale winds such as the sea breeze can lead to the significant influence on micro-scale urban winds. As a result, the application of high-resolution SST to meteorological modeling can contribute large enough to change multi-scale wind distributions over a mountainous coastal region.