Increasing wave power due to global climate change and intensification of Antarctic Oscillation

Abstract

In this study, our objective is to evaluate the long-term variability of global wave power and its underlying mechanisms, utilizing the longest wave reanalysis available (ERA5, 1940–2022). We introduce a novel validation of the global wave power of the ERA5 wave reanalysis against measurements from multi-platform satellite altimeters from 1985 to 2022. This validation shows good agreement over the period. Our analysis shows a consistent increase in global wave power throughout the study period. This rise in global wave power predominantly stems from the influences of global climate change and the intensification of Antarctic Oscillation (AAO) events. As low-pressure systems move southward in the Southern Hemisphere over this period, they generate an increase in wave power 2.6 times larger than the global average increase. This energetic wave power propagates towards the mid and low-latitude regions of the Pacific, Indian, and Atlantic Oceans. This conclusion is verified by an examination of wind wave and swell contributions to wave power. Specifically, the wind wave component (swell) is more (less) important in the Southern Ocean than in the low and mid-latitude regions.