Swell Prediction for the Korean Coast

Abstract

The accurate prediction of abnormally high waves occurring in the East Sea during winter is important in terms of theprevention of coastal disasters along the east Korean coast. This study attempts to hindcast the abnormally high swellwave events that occurred in October 2006 and February 2008 using the unstructured grid wave model UnSWAN withhigh-resolution reanalysis data from the European Centre for Medium-Range Weather Forecasts as meteorologicalinputs. The model used in this study incorporates an additional weighting factor for the relative wave-number indissipation source term to improve swell propagation and wave period. Wave heights and periods are well reproducedcompared with the observational data. Examination of the meteorological data and model results shows that theabnormally high waves in October 2006 were induced by the overlap of a swell wave and a wind-generated wave withnearly the same heading directions; the wave generated in February 2008 was, however, induced by the swell thatpropagated over very long distances from the northeastern area of the East (Japan) Sea due to enhanced atmospheric lowpressure. Use of the reanalysis meteorological data and a wave model equipped with a weighting factor is found to beuseful in identifying the generation mechanisms as well as reasonable estimates of abnormally high wave events.