The mean and extreme tropical cyclone wave climate throughout the Coral Sea, from 1979 to 2020

Abstract

Here we present a mean and extreme tropical cyclone (TC)-generated wave climate for the Coral Sea (the oceanic basin east of Australia), for 1979–2020. An available WAVEWATCH III® hindcast model dataset with surface wind forcing from the National Centres for Environmental Prediction supplied Climate Forecasts System Version 2 was used. The resolution of this wind field is 0.3°, increasing to 0.2° from 2011, among the highest available to better represent TC vortices. The spatial and temporal resolution of the wave model was sufficient to produce TC wave climates, although a limitation in representing TCs at both ends of the intensity scale was apparent. Model performance was validated using wave buoy data at three coastal locations. The area near the Tropic of Capricorn, around 155° E, experienced the largest TC-generated mean waves with the locations of the primary swell height maxima shifted slightly north-west, in comparison with combined waves. There was an interdecadal increase (decrease) in TC significant wave height with positive (negative) IPO phase in three of the four decades. TC extreme wave maxima were situated further east, compared to the TC generated mean waves. The 50 and 100-year average return intervals indicated high extreme waves near the northeastern tip of Australia and northwest of New Caledonia. For the east Australian coast, extreme waves from TCs showed a decreasing trend in the south only. This study presents a unique mapping of TC wave characteristics over the entire Coral Sea and validates the use of a globally applicable method, for such applications.