Effects of Surface Waves and Sea Spray on the Air-Sea Fluxes during the Passage of Typhoon Hagupit

Abstract:

Air-sea exchange plays a vital role in the development and maintenance of tropical cyclones (TCs). Although previous studies suggested the dependences of air-sea fluxes on surface waves and sea spray, how these processes modify air-sea fluxes under TC conditions has never been investigated based on in-situ observations. Using continuous meteorological and surface wave data from a moored buoy in the northern South China Sea, this study examined the effects of surface waves and sea spray on air-sea fluxes during the passage of typhoon Hagupit. The mooring is located within about 40 kilometers of the center of typhoon Hagupit. It is found that surface waves could increase momentum flux to the ocean by about 15%, and that sea spray could enhance both sensible and latent heat fluxes to the atmosphere, making Hagupit gain 500 W/m2 more heat flux from the ocean. These results have significant implication for understanding TC-ocean interaction and improving TC intensity forecasting.