An Improved Sea Spray-Induced Heat Flux Algorithm and Its Application in the Case Study of Typhoon Mangkhut (2018)

Abstract

The prediction of tropical cyclone (TC) intensity has been a lasting challenge. Numerical models often underestimate the intensity of strong TCs. Accurately describing the air–sea heat flux is essential for improving the simulation of TCs. It is widely accepted that sea spray has a nonnegligible effect on the heat transfer between the atmosphere and the ocean. However, the commonly used sea spray-induced heat flux algorithms have poor applicability under high wind speeds, and it is difficult to apply these algorithms to models to forecast TCs. In this study, we proposed an improved sea spray-induced heat flux algorithm based on the FASTEX dataset. This improved algorithm performs much better under high wind speed conditions than the commonly used algorithms and can be used in a coupled numerical model. The addition of sea spray-induced heat fluxes noticeably enhances the total air–sea heat fluxes and allows more energy to be transferred from the ocean to the lower atmosphere. In the simulation of TCs, the addition of sea spray-induced heat fluxes significantly improves the simulation of TC intensity and makes the low-pressure structure and wind field structure more fully developed in the horizontal direction.