摘要
利用日本GMS卫星数据TBB资料、多普勒雷达产品及NCEP逐6小时再分析资料对2013年6月27日20时—29日20时发生在江西省浙赣沿线附近的一次梅雨锋大暴雨过程进行诊断分析。结果表明:(1)中高纬双阻型和副热带高压位置偏南,是引发该暴雨过程的大尺度背景条件,梅雨锋上不断有中小尺度对流系统产生,这些中小尺度对流系统在受到大尺度强迫作用而增强并长时间维持,在导致暴雨区形成强降水;(2)此次过程是发生在不稳定流较弱、强迫流极强的环境下,暴雨区发生在低层西南急流出口区左侧、高层急流入口区,该区域上空具有低层正涡度、高层负涡度和低层负散度、高层正散度的藕合形势,这种形势非常有利于强垂直上升运动的维持,为这次梅雨锋暴雨过程提供了强大的动力机制。
Using of Japanese GMS TBB data, Doppler radar products and NCEP reanalysis by 6hours, Meiyu heavy rain occurred in the vicinity of the Zhejiang-Jiangxi on the June 27 to 29 in 2013 is diagnostic analyzed.The results showed that ： 1） The positions of middle and subtropical latitudes and double blocking souther than usual, which is large- scale background conditions for the heavy rain,mesoscale convective systems which is sustained and enhanced by Large- scale forcing continuously produce along Meiyu edge result from the formation of heavy rainfall in the storm area; 2） This process takes place in the environment of weak stream instability and strong forced flow, Heavy rain occurred in the left of lower southwest jet exit area and level jet entrance region, Over the region has a coupling situation of positive vorticity at Low-level, negative vorticity at High-level and negative divergence at Low-level, positive divergence at High-level, which is very conducive to the maintenance of strong vertical ascending motion and provide a powerful motivation mechanism for this Meiyu rainstorm.
出处
《气象研究与应用》
2015年第3期22-25,I0002,共5页
Journal of Meteorological Research and Application
关键词
不稳定流
强迫机制
中尺度系统
nonsteady flow
Forcing mechanism
Mesoscale systems
