| China Sea which is bordered on the northwest Pacific Ocean is the biggest pericontinental sea and one of the three tropical cyclone cradle lands in the northwest Pacific Ocean. China Sea is divided into Chinese Shelf Sea (Bohai, Yellow Sea and Donghai) and South China Sea by the Taiwan Strait. Its seasons alternate clearly, inshore runoff change frequently, submarine geomorphology is complicated. Therefore, it has the complicate weather, climate feather and the special thermodynamic, dynamical characteristic. The mesoscale air-sea interaction weather phenomenon such as typhoon, passing cyclone happens frequently on this area. It's well known typhoon is a kind of intense mesoscale warm cyclone storm, which happens on the low latitudes. Recent years, many shipwreck accident, which happened on the China Sea area is related to the typhoon. While the reform and opening is sustainable deepening and developing, our littoral importance for the national economy is on the rise;the offshore transport is busier. Furthermore, the SCS and the Yellow Sea are our important marine cultivation area and fishing ground, and yet typhoon brings much loss to the littoral economy and the shipping business. Accordingly, research the effect of air-sea interaction through the typhoon process makes us have a better understanding of air-sea interaction and its physical mechanism, and also can be as the scientific and dependable means to the exact weather forecast and sea environment forecast, which will work for protecting people from life and money damage.In this paper the Mesoscale Coupled air-sea Model MCMvl.O is applied to the China Sea area successfully, and that this model is used to simulate the air-sea interaction processes of five China Sea typhoons. The quantificational effects of air-sea interaction throughout the typhoon process are got by analyzed the simulation results. After the brief introduction of importance and development of coupling model and typhoon research in chapter 1, chapter 2 continues to introduce the two model components for coupling and put emphasis on introduction of MM5V3 model systems on the PC. The following chapter 3 describes the application of MCMvl.O on China Sea area and the quantificationalanalysis on the experiments results for two cases of China Sea typhoon. In chapter 4, 5 cases of typhoon were chosen to do the bulk coupled and no-coupled test, and then compared the results to get the quantificational effects of air-sea interaction throughout the typhoon process. Conclusion section is summarized in chapter 5.The simulation results indicate: the tracks of the cases are improved by the air-sea coupling to some extent. The track error decreases more than 45km for three cases and decreases 18km for one case, increases 200km for one case. However, this effect is not remarkable and irregularity. Air-sea coupling can improve the intensity of typhoon significantly, especially at the end of the test. The intensity errors for the five cases decreases are from 3hpa to 13hpa at 48h. Furthermore, Air-sea coupling makes SST (Sea Surface Temterature) down greatly, the max-extent is about 4°C, with a greater reduction in the center and the right semicircle;Cool water pumping and the wind entrainment induced the reduction of the SST. Air-sea coupling also weakens the warm core, decreases the relative humility and holds back the ascent motion. More than 2°C cooling and 10%-60% humility decrease are found in lower atmosphere layer over the sea surface of maximum SST decrease. Surface wind speed decreases 3m/s-8m/s except high wind zone whereas increases 2-6m/s at typhoon gale zone. The time, location and intensity of heave rain are also modified by air-sea interaction. Maximum difference of precipitation area locates in the right of typhoon track and is relevant with sea surface cooling distribution. Accumulative precipitation from 0 to 48h decreases 20-160mm for convective part while there is no irregular effect for non-convective part. Air-sea coupling leads to SST decrease, results in heat flux decrease. Potential flux is more sensitive than the latent flux to the SST decrease.
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