0216号台风降水及其影响降水机制的数值模拟试验

THE NUMERICAL SIMULATION OF RAINFALL AND PRECIPITATIONMECHANISM ASSOCIATED WITH TYPHOONS SINLAKU (0216)

中文关键词:  热带气旋降水，影响机制，数值模拟

英文关键词:Rainfall associated with tropical cyclone,Impact mechanism,Numerical simulation.

中文摘要:

      文中用MM5模式对0216号台风（森拉克）降水进行了数值模拟，取得了较好的效果。模拟得到的台风降水中心强度和位置以及降水的分布与实况基本相符。文中还对影响热带气旋降水的机制进行数值模拟试验。结果表明：冷空气入侵热带气旋外围可以大幅度增加热带气旋外围及倒槽的降水，但入侵到热带气旋中心附近的冷空气使热带气旋强度减弱，造成中心附近降水明显减少，但其外围与倒槽的降水明显加大；地形作用使迎风坡及降水中心增加雨量，背风坡雨量减少，从而使降水分布更不对称、更不均匀；大陆及其近海的湿度场对热带气旋降水有较大的影响。

英文摘要:

      In this article, numerical experiments of rainfall associated with T0216 (Silaku) are carried out using MM5 numerical model. And the simulations are successful. The simulating precipitation cell intensity and position, precipitation distribution all match with the observations well. For a good understanding of the precipitation mechanism associated with the tropical cyclone, we also carry out many other experiments. The results indicate:(1) When the cold air invades the external part of the tropical cyclone, the precipitation far off the tropical cyclone center and in the inverse trough increases in great quantum. When invading the vicinity of the typhoon center, the cold air reduces the tropical cyclone center intensity, the precipitation near the center decreases prominently, while the precipitation outside the tropical cyclone and in the inverse trough increases notablely. (2) The orographic effect augments the rainfall over the upwind slopes of the mountains, precipitation cell intensity and the precipitation near the tropical cyclone center. It abates the rainfall over the downwind slopes of the mountains. So the orograohic effect makes the precipitation distribution more asymmetric.(3) The humidity field of landmass and region near the sea shore has a great impact on the rainfall associated with tropical cyclone.The results mentioned above will play a valuable role in forecasting the rainfall during a tropical cyclone process.