Impact of Precipitation on the Tropical Cyclone Induced Sea Surface Temperature Cooling in Coupled Atmosphere-Ocean System

Cooling of the upper ocean caused by the tropical cyclone (TC) induced mixing is an important process of air-sea interaction that can affect TC intensification. In the state-of-the-art modeling systems, the atmospheric and oceanic model components are coupled through the fluxes of momentum and heat at the atmosphere-ocean interface. One of the atmospheric processes that may substantially modulate the air-sea interaction and the storm induced sea surface temperature (SST) cooling is the heavy precipitation produced by a TC. Precipitation not only increases the static stability of the upper ocean to affect vertical mixing in the ocean mixed layer but also exerts an impact on surface momentum, sensible heat, and latent heat fluxes. Estimation from observations and a simple linear model suggests that TC rainfall can have a non-negligible effect on the SST cold wake induced by a TC. To date, the potential impact of precipitation on air-sea interaction has not been included in any coupled modeling system used for TC prediction. In this study, we made an attempt to include the effect of precipitation on the exchange at the atmosphere-ocean interface and the upper ocean in the Weather Research & Forecasting (WRF) model coupled with a three-dimensional upper-ocean circulation model and tested it in the simulations of a couple of well observed and documented TCs.