An investigation of the effects of wave state and sea spray on an idealized typhoon using an air-sea coupled modeling system

In this study, the impact of atmosphere--wave coupling on typhoon intensity was investigated using numerical simulations of an idealized typhoon in a coupled atmosphere--wave--ocean modeling system. The coupling between atmosphere and sea surface waves considered the effects of wave state and sea sprays on air--sea momentum flux, the atmospheric low-level dissipative heating, and the wave-state-affected sea-spray heat flux. Several experiments were conducted to examine the impacts of wave state, sea sprays, and dissipative heating on an idealized typhoon system. Results show that considering the wave state and sea-spray-affected sea-surface roughness reduces typhoon intensity, while including dissipative heating intensifies the typhoon system. Taking into account sea spray heat flux also strengthens the typhoon system with increasing maximum wind speed and significant wave height. The overall impact of atmosphere--wave coupling makes a positive contribution to the intensification of the idealized typhoon system. The minimum central pressure simulated by the coupled atmosphere--wave experiment was 16.4 hPa deeper than that of the control run, and the maximum wind speed and significant wave height increased by 31% and 4%, respectively. Meanwhile, within the area beneath the typhoon center, the average total upward air--sea heat flux increased by 22%, and the averaged latent heat flux increased more significantly by 31% compared to the uncoupled run.