The Ideal Tropical Cyclones Numerical Simulation Study

This paper discuss the effect of roughness coefficient on the tropical cyclone landfalling process using a idealized TC model developed from PSU/NCAR MM5 in the condition of quiescence and f-plane atmosphere. In order to understand the different influences of land and sea surfaces in the TC landfalling process,two kind of experiments had been designed:one for settled TC, the other for movable TC,and each kind consists four tests.The result indicates that the distribution of wind, precipitation, warm core and intensity of tropical cyclone has been changed obviously due to the effect of difference between the land and sea. The roughness coefficient experiments indicate that the change in tropical cyclone intensity will be varied with different coefficient. Also the experiment indicates the wind of tropical cyclone is reduced by the land and the effect of an tropical cyclone landfalling process could result in the height increasing of tropical cyclone boundary layer. As for moving TC,its symmetry somely rusume after landfalling.The different distributing between ExpB2 and ExpB3 is much smaller than the other Exps of the same group, so it is shown that if the roughness coefficient come to a certain number, the effect of roughness maybe not take the leading key in TC decreasing process any more.