湿位涡在一次北疆暴雪天气中的应用  

Application of Moist Potential Vorticity for a Snowstorm Forecast in Northern Xinjiang

作　　者：吕新生 王莹[1,2] 李圆圆 唐冶 杨霞 

机构地区：[1]新疆气象台,新疆乌鲁木齐830002 [2]马鞍山市气象局,安徽马鞍山243000

出　　处：《沙漠与绿洲气象》2012年第5期7-11,共5页Desert and Oasis Meteorology

基　　金：公益性行业(气象)科研专项(GYHY201106007)

摘　　要：2010年2月22—24日北疆出现了一次暴雪天气过程。基于高空和地面实况、欧洲中心数值预报、NCEP资料对环流形势、低层风场、假相当位温、湿位涡进行分析,结果表明:极锋锋区与副热带锋区在新疆汇合是产生暴雪的主要原因,低层辐合为暴雪提供了足够的上升动力条件,极锋锋区上的冷空气和北疆上空的垂直风切变为暴雪提供了不稳定条件。暴雪发生常伴随在北疆低层大的能量锋区附近,暴雪落区在700 hPa负的湿位涡中心值附近,可以把它作为暴雪落区预报的一个参考指标。Based on the observed data and the reanalysis dataset from the NCEP/NCAR reanalysis project, the mechanism of a snowstorm happened on February 22-24, 2010 in Northern Xinjiang was studied. The circulation,low-level wind,pseudo-equivalent potential temperature and moist potential vorticity. Were andyzed the results showed that the synodic motion of polar front zone and subtropical front zone in Xinjiang is the main reason of the snow storm.The convergence in the low layer provided enough dynamic conditions for the blizzard.The cold air from the polar front zone and the vertical wind shear over the Xinjiang region provided unstable conditions for the blizzard. Blizzards often occur with big energy frontal zone in low-level atmosphere and near the negative center of the moist potential vorticity in 700 hPa, the area of blizzard. which can be a reference designator to forcasting

关 键 词：暴雪 假相当位温 能量锋区 湿位涡 

分 类 号：P458.121[天文地球—大气科学及气象学]