Hemispheric Asymmetry in Future Wave Power Changes: Seasonality and Physical Mechanisms

Abstract This study inspects the global changes in ocean wave power (WP) by the end of the 21st century, relative to the 1979–2005 period, focusing on seasonality and physical mechanisms. The multimodel ocean wave simulations from WAVEWATCH‐III, forced with surface winds simulated by seven different CMIP5 global climate models, are particularly examined. These models robustly show a hemispheric asymmetry in WP changes, that is, a decrease in the Northern Hemisphere but an increase in the tropics and Southern Hemisphere, with large seasonal and regional variations. Individual terms of differential WP, which include wave height and wave period changes, are analyzed to isolate the role of each process. Although wave height changes dominate the overall WP changes, wave period changes also play a comparable role in the Southern Hemisphere extratropics especially in the Indian Ocean sector dur…