“碧利斯”台风暴雨物理量场诊断分析

ANALYSIS OF PHYSICAL VARIABLES OF THE RAINSTORM OF 0010 TYPHOON“Bylis”

本文用MM5模式数值模拟了0010号“碧利斯”台风登陆福建的过程,表明MM5模式能很好地模拟出主要雨带及其分布特征。物理量场分析指出,本次福建沿海地区暴雨产生的物理机制主要有:台风登陆福建前后福建沿海地区上空层结相当不稳定;由于台风环流非对称性,台风中心北侧中低层有很强的风速、相对湿度、正涡度、辐合、垂直速度;暴雨区高低层存在正负螺旋柱;暴雨区高层存在正湿位涡、低层负湿位涡中心。

This paper used MM5 to simulate the process of landing of 0010 Typhoon “Bylis”. It showed that MM5 can simulated main rainstorm belt and its’distribution characteristic very well. The analysis of physical variables indicated that this main mechanisms of rainstorm happened in the coastland of Fujian Province were:the layer above the Fujian coastland quite unsteady before and after typhoon landing;because of typhoon’s unsymmetrical circumfluence, strong wind speed, relative humidity, positive vorticity、convergence and vertical velocity uppeared at the north of typhoon’s center,between the higher and lower layers of rainstorm positive and negative helicity column exists,belween positive moist potential vorticity center exists at high layer, and negative moist potential vorticity center exists at the low layers.