摘要
利用NCEP再分析资料和常规观测资料,对2006年7月13日和2012年7月29日2次发生在贺兰山东麓的大暴雨天气过程进行天气学分析,并对物理量场进行诊断分析,得出造成宁夏暴雨的主要影响系统有副热带高压、青藏高压、西风槽、西风急流.其中,副热带高压为暴雨提供充沛的水汽与能量,青藏高压提供了高空辐散场的维持机制和次级垂直环流的加强作用;700 hPa相对湿度≥80%为宁夏暴雨出现的必要条件,而相对湿度≥90%是大暴雨出现的必要条件;当暴雨发生时,暴雨区上空存在低空辐合高空辐散的垂直结构和次级环流;抬升指数LI均对强降水的预报有较好的指示意义.
Using NCEP reanalysis data and conventional observations, weather was analyzed and its physical fieldis were diagnosticed and analyzed for two rainstorm processes in Ningxia on July 13, 2006 and July 29, 2012. Results showed that the principal influence systems were Subtropical high, the Tibetan high, westerly trough and upper jet stream. Subtropical high provided water vapor and energy; the Tibetan high provided maintenance condition of high-altitude divergence and secondary vertical circulation. Prerequisites for Ningxia rainstorm are 700 hPa and RH≥80%, prerequisites for heavy rainstorm are 700 hPa and RH ≥90%. During rainstorms, the vertical construction and secondary circulation of low altitude convergence and high-altitude divergence exist on storm area sky. Lift index, LI is better indicator for rainstorm prediction.
出处
《宁夏工程技术》
CAS
2014年第3期204-211,共8页
Ningxia Engineering Technology
关键词
暴雨
对比分析
天气学方法
诊断分析
rainstorm
comparative analysis
synoptic method
diagnostic analysis
