Linear trend in the wave climate of the East Sea estimated from a 40-year high-resolution wave hindcast

Abstract

Changes in ocean wave climate play a crucial role in the coastal environments such as coastline change and coastal erosion. In this study, we investigate 99th percentile significant wave heights (SWH) (a measure for extreme SWHs), peak wave period (PWP), and peak wave direction (PWD) in the East Sea, using a 40-year (1979~2018) wave hindcast data simulated from a high-resolution wave model (SWAN) forced with the ERA-Interim wind fields. In association with the substantial seasonality in wind fields by the East Asian monsoon, the long-term means of wave properties (SWH, PWP, PWD) and trend of 99th percentile SWHs appear to significantly differ on the seasonal timescale. In addition, PWP shows an increasing trend in most of the East Sea, except for the northern East Sea during August to October showing a decreasing trend. Our findings suggest that while the PWP tends to increase in most of the East Sea except the northern area from August to October, the long-term trends of the 99th percentile SWH in the East Sea could considerably different depending on regions and seasons.