摘要
为研究华北暴雨形成时的中尺度与微尺度的结构特征,选取发生于2005年7月22-24日的一次华北暴雨过程为研究对象,利用1°×1°的NCEP再分析资料和0.05°×0.05°的FY2C红外TBB资料,对此次暴雨过程发生时的天气形势、水汽输送、大气稳定度、云场特征进行了分析。结果表明:此次暴雨过程是在登陆台风和西风槽的共同影响下产生的,高空槽后的西风急流入侵到华北北部,低层副高西侧的东南急流位于华北东部,使得华北地区上空形成了有利于触发对流的低层辐合和高层辐散的天气形势。低层印度季风与我国南海夏季风对水汽的北上有重要作用,还有一部分水汽系来自副高西侧的东南风急流输送;高层水汽主要是由偏东气流经副高西侧向西,然后转向北输送到华北;华北地区的低层存在较强的水汽辐合,高层存在相对较弱的水汽辐散区,这为暴雨发生提供了必要的水汽条件。
In order to research mesoscale and microscale structural characteristics of rainstorm in North China, a rainstorm case happening on 22 - 24 July 2005 in North China is selected. Characteristics of weather situation, water vapor transport, atmospheric stability and clouds field were analyzed in detail by using 1°× 1° NCEP reanalysis data and TBB infrared data of FY2C satellite with 0. 05°× 0.05° resolution. The research results show that this rainstorm process is caused by influence of interaction between landing typhoon and westerly trough. Westerly jet flow behind upper trough stretch to the north of North China, and low level south - east jet flow lie in the east of North China, which is favorable to forming of low-level convergence and high-level divergence. Indian monsoon and South China Sea summer monsoon play important role in low-level water vapor northward transport into North Chi- na, and south - east jet flow existing in the west of subtropical high also transport water vapor partly. In the high level, water vapor mostly comes from east wind flow and transport northward and westward along the west of subtropical high. Strong water vapor convergence in the low level and weak divergence in the high level above North China create a good vapor condition for the occurrence of the rainstorm.
出处
《自然灾害学报》
CSCD
北大核心
2010年第1期61-69,共9页
Journal of Natural Disasters
基金
国家自然科学基金资助项目(40475006)
关键词
暴雨
中尺度结构
位涡
水汽
华北
rainstorm
mesoscale structure
potential vorticity
water vapor
North China
