1011号台风“凡亚比”登陆过程数值模拟及诊断分析

利用中尺度非静力数值模式WRF V3.2.1对“凡亚比”台风(1011)的登陆过程开展了高分辨率数值模拟,模拟采用三重嵌套,最高分辨率为3 km,共积分120 h(5 d)。利用收集到的观测资料对模式模拟的结果进行了较细致的对比验证。结果表明,模式较好地模拟再现了“凡亚比”台风的发展演变以及两次登陆过程,模拟的台风路径与观测路径较为一致,模式也较好地把握住了“凡亚比”台风的强度演变过程,模拟取得了初步的成功。进一步利用高分辨率模拟资料对此次台风登陆过程的强降水开展了初步诊断分析,结果表明,在整个研究时段内,散度垂直通量绝对值的垂直积分<|Q|>与地面降水区有很好的对应,两者在空间分布和时间演变上比较一致,在降水大的区域<|Q|>的值也大,这表明<|Q|>对“凡亚比”台风强降水具有较好的诊断和指示意义。

Numerical Simulation and Diagnostic Analysis of Landfall Processes of Typhoon Fanapi (1011)

Typhoon Fanapi, a super typhoon that generated over the Northwest Pacific and the South China Sea in 2010, is the only typhoon to make landfall twice in China. Intense precipitation brought by Fanapi caused severe damages in Taiwan and in Fujian and Guangdong provinces. In this study, the Weather Research and Forecasting (WRF) model is used to simulate typhoon Fanapi at high resolution (finest grid size of 3 km) with three nests for 120 hours. Detailed comparisons are obtained between observations and the simulation. The results show that the simulation reproduced the development, evolution, and twice-landfalling processes of typhoon Fanapi to a significant degree. The simulated track and intensity evolution are shown to be rather similar to those of observations. Futhermore, the high-resolution simulation data is used to perform diagnostic analysis on the heavy rainfall occurring with typhoon Fanapi. Results indicate that the <|Q|> parameter agrees fairly well with observed precipitation in spatial distribution and time evolution. This parameter shows strong signals over the heavy rainfall region and weak or no signals over other regions; therefore,<|Q|> is an important indicator in the diagnosis of heavy precipitation of typhoons.