A numerical forecast system for ty phoon storm surge over China coast

A numerical forecast system for typhoon storm surge over China coast is develope dbased on the threedimensional baroclinic ocean circulation model of POM (Pri nceton Ocean Model). As the forced field, the forecasting wind field of typhoo nover sea surface is constructed by a model developed by Shanghai Typhoon Insti tute. The effect of typhoon motion and the environmental wind field are consider ed and a more reasonable formula of wind stress under strong wind is applied. By numerical simulations with more than 37 typhoon storm surge processes over Chin a coast, it can be concluded that it works well to recur the storm surge elevati on of observations. The average errors between the simulated and observations are 17, 21 and 25 cm for whole process, within 10 h around the maximum water risin g and at the maximum water rising time respectively. The time for maximum sea le vel increment appearing in simulation is basically consisted with the observatio ns and the average error is about 1 h. Generally the maximum sea level increment of simulation is smaller than observations especially in the condition of much strong storm surges with more than 200 cm sea level increment. For the process w ith double-peak structure, only the larger one is well simulated, although some times the smaller one exists in the simulation. Because of the relatively short simulation period, the value of simulation is a little small during forerunner c onsidering the case that surge has already get rise at the beginning of the simu lation, but it usually works well only if the time span of forerunner is not too short. According to the model result in recent 2 years, it is found that this o perational system can accurately predict the storm surge. An automatic manage pr ocess is build from data acquisition to model running and results output. The ou tput is displayed both in the form of MICAPS (Meteorological Information Compreh ensive Analysis and Process System), which is as the meteorological operation pl atform, and pictures which are shown on internet.