0414号台风“云娜”的数值模拟

利用美国CAPS的非静力高分辨率区域预报模式(ARPS)对0414号台风"云娜"进行数值模拟,其中把新一代多普勒天气雷达资料分析引入模式,模拟结果表明ARPS模式能较好模拟台风"云娜"的移动路径、中心气压强度变化及台风大暴雨;并利用模式输出的组合反射率与雷达组合反射率资料比较来检验模拟结果.数值模拟结果表明台风自身结构是引起0414号台风西折路径的重要原因;浙南闽北地形对0414号台风的影响作地形敏感性试验结果表明浙南闽北地形使0414号台风移动路径出现右偏现象;浙南闽北地形对0414号台风强度影响较小,地形对深入内陆后台风强度变化有较明显的影响;浙南闽北地形对0414号台风暴雨有增幅作用,降水分布更加不均匀.

A NUMERICAL SIMULATION STUDY OF TYPHOON RANANIM

Using the high resolutions non-hydrostatic model ARPS,the typhoon Rananim(0414) was simulated by using the Cinrad Doppler radar data,the results before and after typhoon landfall show that ARPS performs well to simulate the track,the variation of center pressure as well as the severe heavy rain of Rananim.Meanwhile,the simulated composite radar reflectivity was compared with radar observed composite reflectivity.The numerical results reveal that the asymmetrical structure of Rananim plays an important role in it's westward deflecting after landfall.The sensitivity simulation experiments of terrain effect on Rananim were also investigated,the terrain of the Southeast China forces Ranarim turning right slightly on its motion and increased its intensity obviously when typhoon is far away from the coastline,while the terrain only impacts slightly on storm intensity when it landfall.The results show that topographic lifting contributes greatly to precipitation enhancement,and makes its distribution of precipitation more uneven.