云南初春极端冷暖灾害事件的对比分析  

The contrast analysis of the cold and warm extremely disaster events in early spring of Yunnan

作　　者：彭贵芬[1] 杨素雨[1] 周国莲[1] 刘瑜[2] 

机构地区：[1]云南省气象台,云南昆明650034 [2]云南省气候中心,云南昆明650034

出　　处：《云南大学学报（自然科学版）》2010年第3期308-313,共6页Journal of Yunnan University(Natural Sciences Edition)

基　　金：国家自然科学基金资助项目(40675056);中国气象局气候变化专项(CCSF-09-4);云南省气象局青年研究基金项目(Q200805)

摘　　要：利用云南1961～2009年2月的平均气温资料,采用异常指数对云南2008,2009年初春出现的极端低温雨雪冰冻和极端高温少雨干旱灾害事件做了空间分布、历史排位、冷暖异常趋势分析;利用NCEP/NCAR再分析资料,分析了云南省2008年和2009年初春极端冷暖异常灾害事件天气成因.结果表明:2008年初春是近40年来的最冷年,2009年初春则是有气象记录以来的最暖年;云南初春东部平均气温从20世纪80年代以来有向暖异常演变的趋势,2000年以来,极端暖异常现象十分突出.北半球东亚中高纬500hPa高度距平场2008年2月呈"正负正"、2009年2月呈"负正负"的相反分布.乌山阻高异常偏强,冷空气活动频繁,南支槽异常偏强,导致2008年初春云南极端异常低温冰雪灾害;而乌山阻高偏弱,东亚大槽异常偏东,冷空气主体偏东,印度副高异常偏强,南支槽异常偏弱,导致云南2009年初春极端高温异常干旱灾害.Based on the February average temperature data from 1961 to 2009 of Yunnan and the abnormal index,we analyzed the space distribution,the history rank and the anomaly cold and warm tendency of the disaster events that induced by the extreme low-temperature,the sleet and the frost in 2008 and the extreme high-temperature dry in 2009.Besides,we analyzed the cause of the disaster events by using the NCEP/NCAR reanalysis data.The results show that within meteorological phenomena records,it was the coldest year in the past 40 years in early spring of 2008,but the warmest year was in early spring of 2009.The eastern average temperature in early spring in Yunnan tends to warm since the eighties of the 20 th century and the warm extremely phenomenon was fairly outstanding since 2000.Analyzing the reasons of the disaster events,we believed that there was a prominent difference in the circulation field of mid and high latitude in Northern Hemisphere in February of 2008 and 2009.The height departure distribution was ＇＋-＋＇ on 500hPa in eastern Asia in February of 2008,but ＇-＋-＇ in February of 2009.The direct reason of the extreme low-temperature,the sleet and the frost was that Ural Mountains blocking high and southern branch trough was exceptionally stronger,and the cold air activity was frequent,which gave rise to the continual low-temperature and accumulative precipitation in early spring of 2008.The another direct reason of the unusual high-temperature in early spring of 2009 was that Ural Mountains blocking high was exceptionally weaker than normal,as well as East Asia trough and the cold air activity were more eastward,which leaded to the few precipitation in Yunnan.

关 键 词：云南初春 极端冷暖 异常指数 气候趋势 成因 

分 类 号：P423[天文地球—大气科学及气象学]