We will discuss new strategies for modeling the coupled atmosphere-wave-ocean processes in tropical cyclones. The new approach combines explicit modeling of the wind-wave-current interaction processes and sea spray effects near the air-sea interface with very high-resolution modeling of the marine boundary layer (MBL) processes. The key element of our coupled modeling approach is the air-sea interface model (ASIM) developed by our research group at URI that consists of the wave boundary layer model and the air-sea energy and momentum flux budget model. The ASIM is embedded into the TC-wave-ocean coupled model and calculates all the flux boundary conditions for the atmospheric, wave and ocean models.

Another key element of the new coupled model is a 2-D LES boundary layer model that is embedded into the 3-D TC model to explicitly resolve roll vortices in MBL. This approach to parameterization of roll vortices resembles a recently emerged approach of “super-parameterization” of the cloud physics processes in GCMs and can be called super-parameterization of the TC MBL. The processes at the air-sea interface (e.g., wave breaking, fluxes, spray generation) and those in the MBL (e.g., roll vortices, sea spray transport and thermodynamics) are strongly coupled. In particular, breaking waves occur intermittently and their impacts (spray generation, enhanced form drag) are localized and intense. Therefore, the interaction between breaking waves and roll vortices significantly modifies their effects on the surface processes and MBL dynamics.