轴对称模型台风的改进方案及其对0425号台风数值模拟的效果

IMPROVED SCHEME OF AXISYMMETRIC TYPHOON BOGUS MODEL AND ITS IMPACT ON NUMERICAL SIMULATION OF NO.0425 TYPHOON

关键词:  切向风廓线的改进  MM5模式  0425号台风“洛坦”  路径和强度模拟

Key words:  improvement of tangential wind profile  MM5 model  NO0425 typhoon NOCKTEN  Simulations of track and intensity

摘要:

西北太平洋台风切向风廓线存在明显的差异,目前MM5中尺度数值模式NCAR-AFWA的模型台风(bogus)方案中仅使用了最大风速和最大风速半径两个参数,有时不能准确地描述台风的外围结构。通过引入十级风圈平均半径和七级风圈平均半径对NCAR-AFWA的bogus切向风廓线进行改进,然后对0425号台风"洛坦"的路径和强度进行模拟,结果发现:在台风bogus切向风廓线中同时引入十级风圈平均半径和七级风圈平均半径对台风路径和强度模拟均有改进,同时对台风大风范围的模拟也有改进。

Abstract:

There is distinct difference in the tangential wind profile between different typhoons in the western North Pacific. At present,only two parameters,maximum wind and radius of maximum wind,are used in NCAR-AFWA bogus for MM5 mesoscale numerical model. So sometimes the outer structure of typhoon cannot be described accurately. The tangential wind profile of NCAR-AFWA bogus is improved by introducing radii of 25.7 m/s and 15.4 m/s,and then the track and intensity of No.0425 typhoon(NOCKTEN) are simulated. The results show that the simulations of track and intensity of typhoon both have been improved by introducing the radii at the same time in the tangential wind profile of typhoon bogus. At the same time,there is improvement in the gale wind range of typhoon simulated.