Long–term wave characteristics and wave energy shares by wave type in selected seas in Southeast Asia using reanalysis data

This study examines a number of wave characteristics using WAVERYS reanalysis data for selected four seas in Southeast Asia, which are Gulf of Thailand, Andaman Sea, Malacca Strait, and Lower South China Sea. The emphasis was given to the Gulf of Thailand. The wave characteristics include total wave height/period, swell height/period, and wind wave height/period, WAVERYS evaluation, energy potential shares, long–term averages, joint occurrence between wave height and wave period, monthly variation, and extreme value analysis using the generalized extreme value (GEV) distribution fitted with the regional annual maxima of total wave height. The WAVERYS data show overall reasonable quality for use. The heights of all wave types (here, total waves, swells, and wind waves) are relatively high in Andaman Sea and Lower South China Sea. Over these two seas, swells dominate in terms of height but, over the Gulf of Thailand, swells and wind waves are more mixed. Total wave height in the Gulf of Thailand shows strong seasonality and peaks twice when the regional two monsoons being strong. The extreme value analysis tested eight GEV models (1 stationary and 7 nonstationary) for the Gulf of Thailand, suggesting the adequacy of the stationary model for use to predict the return level of extreme wave height. The results presented here are part of ongoing research and subject to further improvement.