The Influence of Sea Surface Temperature and Waves on Mesoscale Vortices in Typhoon Eyewalls

A fully-coupled system including air-sea interaction, air-wave interaction and wave-current interaction has been developed to focus on the structure of mesoscale vortices in the eyewall of typhoon ‘Kaemi’ (2006). Mesoscale vortices are one type of interior factors influencing the asymmetry of typhoon eyewall; they are closely related to vertical wind shear (VWS) and are impacted by the underlying sea status. Updraught develops on the downshear right and gradually weakens after it reaches its strongest level on the downshear left. Excluding the response of sea surface temperature (SST), larger heat fluxes at the air-sea interface induce the intensification of convection in the typhoon eyewall; however, the region with the most convection still lies on the downshear of the VWS, which is not significantly influenced by the magnitude of heat fluxes at the air-sea interface. In the calculation of sea surface roughness without the effect of waves, the asymmetry of the eyewall weakens, and mesoscale vortices distribute uniformly in the azimuthal direction above a shorter sea surface roughness.