Surface wave height regulated by ocean currents: An observational perspective

Abstract

Ocean currents exert notable influences on surface wave height through wave-current coupling. In this paper, we provide solid evidences that ocean currents can regulate the significant wave height (SWH) by comparing measurements of a fleet of surface drifting wave buoys (DrWBs) with GFS-WW3 model product. In the Kuroshio Extension (KE) of Northwestern Pacific, the SWH observed by DrWBs are shown to be generally lower (higher) than that simulated by GFS-WW3 when waves propagate towards (against) the direction of surface currents. It is indicated that the GFS-WW3 product could be underestimated/overestimated by up to 5% compared with observed SWH if the forcing from current field is not involved. Adopting altimeter derived data, further analysis shows consistent relationship between observed and modelled SWH in the global ocean, except for regions where ocean swells dominate. The findings may help improve wave model simulations without increasing computational burdens if this relationship is considered.