Presenter: Tetsu Hara (University of Rhode Island)

Description:
Tropical cyclone (TC) intensity is strongly affected by the air-sea heat flux beneath the storm. Therefore, accurate predictions of upper ocean responses (such as mixed layer deepening, upwelling, and sea surface temperature cooling) under TCs are necessary for improving TC intensity forecasts. In this study impacts of surface waves (the sea-state dependent Langmuir turbulence, the air-sea momentum flux budget, and the wave-current interactions) on upper ocean responses under TCs are investigated by combining upper ocean observations (using EM-APEX floats and Lagrangian floats deployed under five tropical cyclones) and a coupled ocean-wave (Modular Ocean Model 6 - WAVEWATCH III) model. The results show that the mixed layer turbulent kinetic energy is significantly enhanced by surface waves (Langmuir turbulence). The results also suggest that the Langmuir turbulence and the other surface wave effects modify the mixed layer deepening and other three-dimensional upper ocean responses.