A Coupled Atmosphere-Wave-Ocean Modeling System: Simulation of the Intensity of an Idealized Tropical Cyclone

A coupled atmosphere-wave-ocean modeling system (CAWOMS) based on the integration of atmosphere-wave, atmosphere-ocean, and wave-current interaction processes is developed. The component models consist of the Weather Research and Forecasting (WRF) model, the Simulating Waves Nearshore (SWAN) model, and the Princeton Ocean Model (POM). The coupling between the model components is implemented by using the Model Coupling Toolkit. The CAWOMS takes into account various wave-related effects, including wave state and sea-spray-affected sea surface roughness, sea spray heat fluxes, and dissipative heating in atmosphere-wave coupling. It also considers oceanic effects such as the feedback of sea surface temperature (SST) cooling and the impact of sea surface current on wind stress in atmosphere-ocean coupling. In addition, wave-current interactions, including radiation stress and wave-induced bottom stress, are also taken into account. The CAWOMS is applied to the simulation of an idealized tropical cyclone (TC) to investigate the effects of atmosphere-wave-ocean coupling on TC intensity. Results show that atmosphere-wave coupling strengthens the TC system, while the thermodynamic coupling between the atmosphere and ocean weakens the TC as a result of the negative feedback of TC-induced SST cooling. The overall effects of atmosphere-wave-ocean coupling on TC intensity are determined by the balance between wave-related positive feedback and the negative feedback attributable to TC-induced SST cooling.