“海棠”台风(2005)雨强差异成因分析

Analysis on the cause of rainfall intensity difference of typhoon Haitang(2005)

通过对暴雨(A1)、大暴雨(A2)及特大暴雨(A3)区中潜热(大尺度潜热加热和对流潜热加热)、改进的湿Q矢量(Q*)以及地形因子(地形抬升和地表摩擦)作用的计算及对比分析,定量探讨了"海棠"台风(2005)雨强差异成因。结果表明,潜热加热在整个台风登陆过程中,基本都有助于A2与A1之间雨强差异形成,且在台风登陆后约1/3时段内对A1、A2及A3之间雨强差异形成有明显贡献。对于Q*矢量强迫作用,台风登陆前,仅有助于A2与A1之间雨强差异形成,在台风登陆后,则对A1、A2及A3之间雨强差异形成贡献明显。地形因子作用在台风登陆前,仅有助于A3与A1、A2之间雨强形成差异,但在台风登陆后,则有利于A1、A2及A3之间雨强差异形成。

By calculating and comparing effects of condensation heating, modified moist-ageostrophic Q vector （ Q^＊ ）, and topographic forcing among three categories of heavy rainfall： heavy rainfall （R1 ）, large heavy rainfall （R2 ）, and extremely heavy rainfall （R3 ）, the cause of rainfall intensity difference associated with typhoon Haitang （2005） is analyzed quantitatively. The results show that latent heating contributes to differences in intensity between R1 and RE during the whole landfall, and among three rainfall categories after the landfall. The forcing from Q^ ＊ vector accounts for differences in intensity between R1 and RE before the landfall while it contributes to differences in intensity among three rainfall categories after the landfall. The topographic lifting is responsible for differences in intensity among R3 and R2 ,Rl before the landfall whereas it contributes to differences in intensity among three rainfall categories after the landfall.