2008年中国南方雪灾与平流层极涡异常的等熵位涡分析  

Analysis on Isentropic Potential Vorticity for the Snow Calamity in South China and the Stratospheric Polar Vortex in 2008

作　　者：易明建[1] 陈月娟[1] 周任君[1] 邓淑梅[2] 

机构地区：[1]中国科学技术大学地球和空间科学学院,安徽合肥230026 [2]安徽省气象科学研究所/安徽省大气科学与卫星遥感重点实验室,安徽合肥230031

出　　处：《高原气象》2009年第4期880-888,共9页Plateau Meteorology

基　　金：国家自然科学基金重点项目(40633015);青年基金项目(40705014;40805024)共同资助

摘　　要：2008年1月中国南方遭遇罕见的大范围冰冻雨雪灾害,本文利用NCEP/NCAR逐日再分析资料和等熵位涡分析方法,分析了这次冰雪灾害期间平流层极涡的变化及其对对流层的影响。结果表明:平流层极涡在2007年12月已经开始增强,到1月中旬亚洲北部极地平流层极涡变得异常强大。高位涡冷空气向南扩展时,沿着倾斜的等熵面运动,从极地平流层上层一直延伸到中低纬度对流层。低层高位涡冷空气主体比较靠北,华北一带为低位涡区;南方为高位涡区,呈东北—西南向伸展,引导北方高位涡主体冷空气和西南暖湿气流在此汇合,引起大范围降温和降雪。An exceptionally serious snow calamity occurred in the south part of China in January 2008, the isentropic potential vorticity （IPV） analysis was performed to investigate the variation of stratospheric polar vortex and its influence on troposphere during this period. Results show that before the occurrence of the snow storm, the polar vortex in the stratosphere strengthened since last December, and then became very strong and extended to the north of Asia in first ten days of January. When the cold air with high potential vorticity expanded towards south, it moved down along the inclined isentropic surface from upper stratosphere of high latitude to lower troposphere of mid and low latitudes. The main part of high potential vorticity in lower troposphere settled more north, North China was dominated by a low potential vorticity belt; while a high IPV center maintained in south part of China, it extended from northeast to southwest, the cold air from hight latitude and the wet air from southeast converged at the south part of China and resulted in the large-scale cooling and snow storm.

关 键 词：雪灾 极涡 等熵位涡 IPV 

分 类 号：P412.292[天文地球—大气科学及气象学]