Dynamical Analyses,Four-Dimensional Data Assimilation And Numerical Experiment For Typhoon Sea Surface Wind

Typhoon is the best destructive marine-atmosphere system. Typhoon, strong coastal storm tide and billow which are caused by typhoon not only bring severe loss for people lived in coastal areas but also have high effect on transportation and operation on the sea, marine project and fishery. Accurate typhoon sea surface wind is the key point to obtain true wave and storm tide. The prediction accuracy of typhoon sea surface wind still does not satisfy the demand because of untrue sea surface initial data and incomplete physical process in numerical model of typhoon sea surface wind. These affect greatly the simulation and forecast accuracy of wave and storm tide. It is very important and critical to obtain accurate and true typhoon sea surface wind for the favoring and fine development of economy, and it is good to accelerate the study of wave, storm tide and so on. The mesoscale atmospheric numerical model of PSU/NCAR (MM5) possess important status in forecasting disaster weather and get success in heavy rainfall, in this dissertation, combining the different emphasis on the study of typhoon between meteorology operators and marine researchers, coupling free atmosphere and the process of boundary layer and studying the effect of air-sea interaction on typhoon sea surface wind, we took the lead in applying advanced mesoscale atmospheric numerical model (MM5) in the study of typhoon sea surface wind. It is a new jumping-off for the study of typhoon sea surface wind. We combined the analyses and forecast of T63/T106(spectrum model) in the National Meteorology Center with conventional surface and sounding observation data, adjusted logically model parameters, for example, sea surface roughness and so on in MM5. Finally we established a simulation and forecast system for typhoon sea surface wind that is suitable for China Sea. We made use of improved MM5 and had numerical experiment on two typhoons: one is for 9608 Typhoon (HERB), the other is for 9711 Typhoon (WINNIE). The exchange of air-sea heat is important for sea surface wind because we aimed at studying sea surface wind. We discussed for 9608 Typhoon how the surface heat I. respectively. We thought the simulated route accuracy of 9711 Typhoon was lower than that of 9608 Typhoon probably because of untrue initial field of 9711 Typhoon. (2). For the sensible heat and latent heat exchange for 9608 Typhoon, the exchange of heat flux were lower value near the center of typhoon, but it showed higher value area around the typhoon. The heat flux tended to decrease accompanying the decline of the strength of typhoon. On the sea surface, sea always offered heat to atmosphere. The latent heat flux was positive value and higher than sensible heat flux of same time. This showed that moisture flux was more important to typhoon system than sensible heat flux does. We analyzed heat flux evolution character on the different landuse. We found sensible heat flux of land took on the highest value and the peak value appeared at 2 PM; the value of common boundary between water and land took the second place, the value of the sensible heat flux of sea was the lowest. For latent heat flux, the value of land was the highest and the value of land was the lowest. The net radiation flux showed remarkable diurnal variation character. (3). Applying simulated sea surface wind to the study of wave, we found that the...