Ocean response to Typhoon Ketsana traveling over the northwest Pacific and a numerical model approach

Recent satellite data of sea surface temperature and chlorophyll- a concentration are presented in investigating the ocean response to Typhoon Ketsana traveling over the Northwest Pacific in October 2003. A significant characteristic is that the surface chlorophyll- a concentration triggered by the typhoon increased 10 times on average during its five- day stay. Characteristics of ocean response to the typhoon are simulated by the Regional Oceanic Modeling System ( ROMS). The simulations indicate that when QuikSCAT wind data are used to force the ROMS, the model outputs of sea surface temperature, chlorophyll- a concentration in cold pool are underestimated compared with satellite data. However, more accurate wind data under strong wind and heavy rain condition can be derived from the angular momentum model. When those wind data are used to force the ROMS, the model output fits the satellite data much better. At last, it is confirmed that the Regional Oceanic Modeling System with strong wind data from the angular momentum model of wind and moderate wind data from QuikSCAT can correctly simulate both the biochemical and physical responses of the ocean to Typhoon Ketsana traveling over the Northwest Pacific.