【作者】 林卫华；

【导师】 沈桐立；

【作者基本信息】 南京信息工程大学 ， 气象学， 2007， 硕士

【摘要】 本文用MM5模式模拟了2005年登陆福建的台风暴雨过程，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分布与实况基本相符。本次福建沿海地区降水产生的主要物理机制有：(1)台风登陆福建前后福建沿海地区上空层结相当不稳定；(2)由于台风环流非对称性，在中低层上台风中心北侧有较强的急流及相对湿度、正涡度、辐合、垂直速度中心；(3)台风流场的非对称结构，使涡度、散度、垂直速度、位涡等分布也是非对称的，加上福建沿海地形分布特征，直接影响了雨带分布的非对称性。采用不同地形高度来模拟该时段台风降水过程，试验结果显示福建东部沿海的特殊地形对登陆福建中部沿海的台风降水有明显的增幅作用。(a)地形可以增加台风中心及其附近的降水量。对于登陆福建中部沿海的台风，福建东部沿海两大山脉太姥山、戴云山山脉对当地台风暴雨具有明显的增幅作用。(b)地形与地形增高可以使雨量分布更加不均匀。(c)除了西侧的台风外围，特别是海面上的降水增幅与台风中心及其附近的降水变化呈反位相变化关系。(d)台风降水受地形影响呈现出类重力波列式的正负相间的变化分布。最后采用不同对流参数化方案对台风登陆前后台风降水过程的影响，试验表明不同参数化方案对台风暴雨过程的模拟存在差异。当无引入积云对流参数化方案时，因地形抬升作用引起对流性降水的增幅作用就不存在，导致模拟降水的明显减少和位置偏离。不同分辨率模拟出的降水效果存在不同，粗细网格的降水模拟结果非常类似，只不过细网格模拟的降水分布能够更准确、更详尽的描述台风暴雨过程，细网格模拟的降水分布具有更详细的中—β尺度的雨团信息。更多还原

【Abstract】 Firstly, The process of landing Fujian of Typhoon "LongWang" is simulated byusing of MM5v3.6 in this paper. It is showed that MM5v3.6 can simulated mainrainstorm belt and its’ distribution characteristic well. The formation of rainstorm inthe coastland of Fujian province has several main mechanisms:(1) the layer above theFujian coastland quite unsteady before and after typhoon landing;(2)because oftyphoon’s unsymmetrical circumfluence, at the north of typhoon’s heart, there werestrong wind speed, relative humidity, positive vorticity、convergence and verticalvelocity;(3) the higher and lower layers of rainstorm exists positive and negativehelicity column. The result showed that the model made a good effect on eithersimulating Fujian inland or seashore storms. The simulation experiment by controllingterrain showed that it was a great difference between the reinforcement results toinland seashore storm caused by the Fujian local terrain and the terrain made a moreoutstanding reinforcement effect to inland storm.Secondly, the terrain sensitivity test indicated that the special terrain in Fujianeastern coast could enhance the typhoon rainstorm distinctly. (a)The increase ofrainfall near the center of the typhoon has a close relation with the terrain;(b) Terraintendency and height can result in more uniformity of the precipitation distribution ;(c)Expect for the precipitation on the west of periphery of the typhoon. The precipitationenhancement extent appears counter of phase relationship with that of the typhooncenter or near the typhoon, especially on the region of the East Sea;(d) Thedistribution of typhoon precipitation presents the positive ad negative change as thegravity wave column wise under the influence of terrain.Finally, Simulation experiments of precipitation prediction with MM5v3.6’sdifferent parameterization schemes over Fujian. In order to test the forecast capabilityof MM5v3.6, four combinations of two different physical parameterization schemesare used in simulation tests of precipitation prediction. It is discovered that thecombinations of Grell cumulus parameterization and Mixed ice-phase in the secondnested grids are superior to the others, especially the center of downfall andrainstorm. The strongest rainstorm center was resulted in the unsymmetrical structureof typhoon "LongWang" through the structure sensitivity test.更多还原