<
doi:  10.12013/qxyjzyj2016-015
2015年6月皖江东部地区一次梅雨锋暴雨过程分析

Analysis on a Meiyu Front Heavy Rainfall Process over Eastern Wanjiang River in June 2015
摘要点击 428  全文点击 1886  投稿时间:2016-03-02  修订日期:2016-05-20
查看HTML全文  查看全文  查看/发表评论  下载PDF阅读器
基金:  安徽省气象局新技术集成项目(编号:AHXJ201402)
中文关键词:  暴雨,梅雨锋,湿中性层结,次级环流,垂直涡度
英文关键词:  heavy rainfall, Meiyu front, moist neutral stratification, secondary circulation, vertical vorticity
        
作者中文名作者英文名单位
魏 葳Wei Wei马鞍山市气象局, 安徽 马鞍山 243000
陈晓伟Chen Xiaowei马鞍山市气象局, 安徽 马鞍山 243000
高 蕾Gao Lei马鞍山市气象局, 安徽 马鞍山 243000
引用:魏 葳,陈晓伟,高 蕾.2016,2015年6月皖江东部地区一次梅雨锋暴雨过程分析[J].气象与减灾研究,39(2):116-124
中文摘要:
      利用雷达、卫星、地面自动站和NCEP再分析资料,对2015年6月16日皖江东部地区的一次暴雨过程进行分析。结果表明:1) 暴雨过程是在贝加尔湖高压脊稳定维持,以及西太平洋副热带高压稳定少动、500 hPa高空槽东移、低层低涡切变维持和新生、高低空急流耦合、地面中尺度辐合系统稳定维持等十分有利的环流背景形势下产生的。2) 中低层的西南急流旺盛对暴雨过程有重要作用;K指数大值区、800—900 hPa高度内水汽辐合中心与强降水发生区域、时间都有很好的对应关系。高层强辐散中心有利于抽吸机制增强,平均散度的辐合层越厚,强降水越易发生。3) 暴雨产生于梅雨锋南侧湿中性层结。降水增强时,θse锋区增强,低层垂直涡度显著发展,600 hPa高度层以下正涡度增长一倍, 垂直涡度的耦合强迫是湿中性层结下中尺度强暴雨系统发展的动力机制。梅雨锋南侧存在经向垂直反环流,北侧为经向垂直正环流,两支次级环流上升支在暴雨区汇合加强,为大暴雨创造了有利的动力条件。4) 此次暴雨受沿江地区活跃的梅雨锋云带影响,TBB中心值小于-52 ℃的对流云团位于地面辐合线两侧,中尺度雨团位于TBB低值中心梯度区和地面辐合线上及其右侧东南气流中,冷空气南下后雨团位于辐合线北侧东北气流中。5) 发展旺盛、降水效率较高的多个对流单体依次向东移动经过皖江东部地区,形成“列车效应”,造成局地大暴雨。降水强度和西南暖湿气流的强度及持续时间密切相关。
Abstract:
      By using the radar data, satellite data, surface automatic station data and NCEP reanalysis data, a rainstorm process occurred on June 16, 2015 over eastern Wanjiang river is analyzed. Results show that: 1) The heavy rainstorm process occursunder a very favorable circulation background situation: Baikal high and the West Pacific subtropical high remained stable, the 500 hPa trough shifted eastward, low level vortex shear maintained and emerged, high and low altitude jets coupled, ground meso-scale convergence system maintained stably. 2) The strong southwest jet at the middle-lower layer played an important role for the rainstorm process. The high value area of K index,the water vapor convergence center at 800-900 hPa had good corresponding to the heavy rain area. The strong divergence at high level enhanced the pumping mechanism, and the thickness of the average divergence convergence layer was more prone to heavy rainfall. 3) The rainstorm occurred in the wet neutral layer on the south side of Meiyu front. When the rain enhanced, the θse frontal zone enhanced, the low layer vertical vorticity developed obviously, positive vorticity below 600 hPa increased doubly, and the coupling forcing of vertical vorticity was the dynamic mechanism for the mesoscale torrential rain systems development under wet neutral stratification. On the south side of Meiyu front, there was the meridional vertical counter circulation, while on the north side, there was the meridional vertical positive circulation. The two ascending branches of the secondary circulation converged and enhanced in the heavy rain region, which provide favorable dynamic conditions for the torrential rain. 4) The precipitation was affected by the Meiyu front cloud zone from the northwestern edge of the subtropical high, the convective cloud with TBB center value below -52 ℃ located on both sides of the ground convergence line, and the mesoscale rain cluster located in the gradient zone of TBB low value center and the area of the surface convergence line, and also in the southeast flow right of the surface convergence line. After the cold air went down south, the locations of rain clusters moved to the northeast flow north of the convergence line. 5) The vigorously-developed and effeiciently-precipitable convective cells moved eastwards through eastern Wanjiang, and the train effect was formed, which caused the torrential rain. The rainfall intensity was closely related to the intensity and duration of the warm and humid southwest flow .
主办单位:江西省气象学会 单位地址:南昌市高新开发区艾溪湖二路323号
联系电话: (0791)82713175传真:0791-82713175 邮编:330096 Email:qxyjzyj@163.com
本系统由北京勤云科技发展有限公司设计