Numerical Simulations of Wind Wave Growth under a Coastal Wind Jet through the Kanmon Strait

Abstract

The development of a coastal wind jet flowing through the Kanmon Strait and the associated wind wave growth are investigated from a case study on 24?26 July 1999. This study presents a realistic example of fetch-limited wave growth under a developing wind jet outflowing from a terrestrial gap of a coast. A series of numerical simulations are used by one-way coupling between a mesoscale meteorological model and a shallow-water wave model with high spatiotemporal resolutions of 2 km and 1 h. The simulated fields of wind and wave are compared with satellite and in situ observations and it is confirmed that they coincide with observations. A complete picture of the wind jet is obtained from the wind simulations, and wave simulations demonstrate the areal extent of higher waves growing with the development of the wind jet. The wind maximum region is localized and extends downwind. The maximum wave height region is highly localized but located more downwind of the wind speed maximum. The high wave region completely reaches the southern coast of the Korean Peninsula before the strong wind. In the lee of the islands, waves are blocked. The conventional fetch growth of waves holds in waves at the more upwind locations than the highest wave region. The forecasting of localized waves under a coastal wind jet is a case in which adequately high spatiotemporal resolution is required for both the wave simulation and wind input.