基于等熵位涡的浙北地区一次暴雪过程的诊断分析  

Analysis of Isentropic Potential Vorticity for a Heavy Snow Event in North of Zhejiang

作　　者：冯智[1] 周秋林[1] 梅士龙[1] 

机构地区：[1]嘉兴市气象局,浙江嘉兴314050

出　　处：《科技通报》2012年第1期51-57,共7页Bulletin of Science and Technology

摘　　要：利用NCEP/NCAR再分析高度、温度、风场资料及Micaps实况降水、积雪资料,对2010年2月13～14日浙北地区出现的暴雪过程及其成因进行了初步分析,结果表明:500 hPa上西南气流的加强及北部冷空气的渗透导致的冷暖空气交汇是产生暴雪天气的主要环流形势,低层发展东移的低涡与地面倒槽的北上是产生暴雪的主要天气系统,对流层中低层逆温层的出现,为暴雪天气的产生提供了有利的条件。云顶亮温和雷达回波的分布则反映了降雪区的移动。等熵位涡分析表明,降水区域集中在高低位涡区域的交界处。随着位涡高低中心的东移,降水区相应东移,当高位涡区一旦加强南压,降水将趋于减弱直至结束。Using the NCAR/NCEP daily reanalysis data of height, temperature, wind and Micaps data, the analysis of a heavy snow event from 13Feb to 14Feb 2010 in North of Zhejiang is performed.It is found that the combination of southwest flow and northern cold air at 500 hPa is the main reason producing heavy snow. The low vortex at 850 hPa and ground inverted trough are the main weather systems. The inversion layers at lower troposphere provide favorable weather conditions. The analysis of black body temperature and the doppler radar echo describes the movement of snow areas. Isentropie potential vorticity analysis shows that the snow areas concentrate in the junction of high and low potential vorticity region. As the center eastward, the snow areas are corresponding eastward, when the high potential vorticity region strengthen southward, snowfall will tend to weaken until ending.

关 键 词：暴雪 低涡 等熵位涡 

分 类 号：P426.634[天文地球—大气科学及气象学]