GLOBAL STORM SURGE AND EXTREME WAVE CHANGES UNDER WARMING CLIMATE FROM PAST TO FUTURE

Abstract

 For coastal adaptation purposes, it is important to estimate climate change related future changes in extreme sea levels due to storm surge and ocean waves, in addition to sea level rise. In this study, global storm surge and ocean wave simulations forced by hourly surface winds and pressure from global climate model simulations were conducted. The spatial pattern in the long-term trend of annual maximum sea surface height and wave height from the past to the warmer future is predominantly driven by changes in tropical cyclone frequency. In the western North Pacific, future tropical cyclone frequencies are projected to decrease and the annual maximum sea surface height and wave height show a decreasing trend (-20cm/100-yr・-200cm/100-yr). Although very intense tropical cyclones are enhanced in the warmer climate, very extreme storm surge and wave heights do not necessarily increase due to the large natural variability.