摘要
根据2001—2015年秦巴山区由西南低涡导致的强降水个例,采用统计方法、天气学方法、数值模拟等,对影响秦巴山区西南低涡过程进行统计,找出西南低涡的移动、发展与汉中强降水之间的关系,通过数值模拟对2011年8月3—5日陕南区域性暴雨过程进行了分析。结果表明,西南低涡背景下秦巴山区的强降水主要出现在6—9月,占暴雨总发生次数的17%,陕南南部是西南低涡影响频次最高的区域;数值模拟表明,暴雨是在西南低涡及低空西南急流的直接作用下发生发展,低涡和急流的维持为降水中心的低层辐合及与之伴随的上升气流的发展提供了有利条件,低层辐合、高层辐散和正涡度的作用使西南低涡有增强作用。
According to the heavy rainfall caused by southwestern vortex in Qinba mountainou area from 2001 to 2015, the statistical methods, the synoptic method and the numerical simulation were used to statistically analyze the process of the southwest vortex in the Qinba mountainou area, and found the relationship between the movement and development of the southwest vortex and the heavy rainfall in Hanzhong. The regional storm process in southern Shaanxi from August 3 to August 5 in 2011 was analyzed by numerical simulation. The results showed that the heavy rainfall in the Qinba mountain area in the background of southwest vortex mainly occurred in June-September, accounting for 17% of the total number of rainstorm, and the southern part of southern Shaanxi was the highest frequency region of southwest vortex. The numerical simulation showed that the rainstorm was developed under the direct action of southwester vortex and low-level southwestern jet. The maintenance of low vor- tex and jet provided favorable conditions for the low-level convergence of the precipitation center and the deve]opment of the ascending airflow. The low-level convergence,high-level divergence and positive vorticity had enhanced the southwestern vortex.
出处
《安徽农业科学》
CAS
2016年第34期191-193,共3页
Journal of Anhui Agricultural Sciences
基金
中国气象局关键技术集成与应用重点项目(CMAGJ2015M59)
关键词
西南低涡
强降水
变化特征
秦巴山区
Southwest vortex
Heavy rainfall
Variation characteristics
Qinba mountainou area
