“7.19”中国中东部地区暴雨过程诊断分析  

A Diagnostic Analysis of “7.19” Rainstorm over Central and Eastern China

作　　者：宋辞 王蔓 朱家瑾 

机构地区：[1]成都信息工程大学,四川 成都

出　　处：《自然科学》2020年第4期310-318,共9页Open Journal of Nature Science

摘　　要：采用NCEP/NCAR提供的逐日4次的FNL全球再分析格点资料和CMORPH融合逐时降水格点数据,对2016年7月19日发生的大范围强降水过程进行了诊断分析,研究结果表明:受中高纬度稳定的两槽两脊、西太平洋副热带高压,以及青藏高原短波槽的影响,西南涡在四川东部生成。高纬度槽和中低纬度西太副高的稳定维持利于西南涡和华北上空低涡的东移、水汽输送和不稳定能量的积蓄,为暴雨创造了有利条件。湿Q矢量也对未来6 h降水也有很好的指示作用,暴雨区对流层中低层上升运动明显的区域易激发出不稳定层结产生强对流活动,对应强的湿Q辐合,因此湿Q辐合区与降水强度呈正相关。对流层中底层Z-螺旋度正值区大值中心对未来6 h降水落区有较好的指示意义,在水平方向上,Z-螺旋度正值密集区分布和主要降水区仍然保持一致。Z-螺旋度正值区中心对应强辐合上升运动,是暴雨预报的有效物理量。Using NCEP/NCAR daily 4 times the FNL global reanalysis and CMORPH hourly precipitation data, the large-area rainstorm process occurring on July 19, 2016 are the diagnosed and analyzed. The results show that the southwest vortex is formed greatly influenced by the stable two troughs and two ridges over high latitudes, the Western Pacific subtropical high and the short wave trough over Qinghai-Tibet plateau. The stable of high latitude trough and Western Pacific subtropical high over middle and low latitudes are favorable for the eastward movement of southwest vortex and vortex over North China, the water vapor transport and the unstable energy accumulation, and finally create favorable conditions for the occurrence of rainstorm. The wet Q vector also has a good indicator effect on the next 6 h precipitation. In the areas with obvious upward movement in the middle and lower troposphere in the rainstorm area, unstable stratification is easy to be stimulated to generate strong convective activities, corresponding to strong wet Q convergence. Therefore, the wet Q convergence area is positively correlated with the precipitation intensity. The large positive center of Z-helicity area in the middle and lower troposphere has a good indication for the precipitation area in the next 6 hours. The distribution of the positive Z-helicity area in the horizontal direction is consistent with the main precipitation area. The center of positive Z-helicity area corresponds to strong convergence ascending motion, which is an effective physical quantity for rainstorm forecast.

关 键 词：暴雨 假相当位温 湿Q矢量 Z-螺旋度 

分 类 号：P45[天文地球—大气科学及气象学]