环境风垂直切变对热带气旋“碧利斯”的影响  

Influence of environmental vertical wind shear on tropical cyclone Bilis

作　　者：毛丽娜[1,2] 潘益农[1] 

机构地区：[1]南京大学中尺度灾害性天气教育部重点实验室 [2]解放军94353部队气象台

出　　处：《气象科学》2009年第4期507-512,共6页Journal of the Meteorological Sciences

基　　金：国家自然科学基金(40333025)

摘　　要：用WRF中尺度数值模式,对0604号强热带风暴"碧利斯"进行了数值模拟。通过对模拟结果与实况的对比分析,表明WRF模式对强热带风暴"碧利斯"有较好的模拟能力。在整个模拟过程中可以分为两个阶段:第一为发展阶段,其强度不断增强,从热带风暴发展成强热带风暴,环境垂直切变方向从北北东风(NNE)转变为北北西风(NNW),对应涡旋内区的上升运动和降水有一个气旋性旋转,上升运动和降水较分散地分布在切变矢量的两侧;第二为维持阶段,该阶段的强度变化不大,上升运动和降水趋于集中并逐渐向切变矢量左侧偏移,这与早期的一些研究结果相一致,原因是当切变方向变化时,低层的相对流入发生了变化,低层相对流入流出的分布决定了700 hPa上热带气旋内区的上升运动和降水的分布。The Weather Research and Forecasting modeling system （WRF） is used to simulate hurricane Bilis. The simulation included two phases ： first, the developing stage, the intensity of Bilis undergoes remarkable strengthening from tropical storm to severe tropical storm, environmental shear direction changes from NNE to NNW, and a cyclone vortex accompanied precipitation and upward motion in inner core. During the developmental process, upward motion and precipitation distributes in two sides of wind shear vector. Second, the sustaining stage, the intensity of the tropical storm changes little, and they tend to centralize gradually and divert to the left of shear vector, which is in agreement with earlier studies, when the shear direction changes, the inflow at the low level changes correspondingly; as a result, low level convergence and high level divergence appear. The pattern of the flow at low level is determined by the upward motion and the pattern of the precipitation inside the tropical storm.

关 键 词：热带气旋 强度和结构 数值模拟 

分 类 号：P425.6[天文地球—大气科学及气象学]