Numerical Study on the Effect of Warm Ocean Anomalies in the South China Sea on the Heavy Rainfall Event on Hainan Island

Abstract

Abstract The previous work has found that the development of an extended TD, which resulted in an abnormally prolonged and heavy rainfall event on Hainan Island from 1 October to 9 October in 2010, was significantly influenced by warm oceanic anomalies from surface to subsurface layer in the SCS. Numerical experiments using the Weather Research and Forecast Model (WRF) were conducted to understand the mechanisms of TD development during this event. A control experiment with an observed warm SST pattern simulated a reasonably extended TD, while a sensitivity experiment using the climatological SST distribution reproduced only a weak and short-lived TD, thus highlighting the importance of air-sea interactions and persistent warm upper-ocean anomalies for the genesis and intensification of the TD.