1961—2004年青海积雪及雪灾变化  

The Variation of Snow-cover and Snow Disaster in Qinghai During 1961—2004

作　　者：时兴合[1] 李凤霞[2] 扎西才让[1] 郭安红[3] 达成荣[1] 唐红玉[1] 

机构地区：[1]青海省气象台 [2]青海省气象科学研究所,西宁810001 [3]中国气象科学研究院,北京100081

出　　处：《应用气象学报》2006年第3期376-382,共7页Journal of Applied Meteorological Science

基　　金：国家自然科学基金项目(40405022);科技部2002年度社会公益研究专项"我国牧区暴风雪灾害监测预警系统研究";中国气象局气候变化专项(CCSF2005-2-QH22)共同资助

摘　　要：利用1961—2004年青海省海西东部和环青海湖地区地面气象观测资料和北半球500 hPa高度场网格点资料,整理了地表积雪序列和雪灾年表,并对积雪的年代际变化特征和雪灾发生的机理及其成因进行了研究。结果表明:海西东部和环青海湖地区出现区域性雪灾的几率为15.9%(7/44),而出现局部雪灾的几率仅为9.1%(4/44)。海西东部和环青海湖地区近44年来冬季累计积雪量的缓慢增加易形成雪灾和低温冻害。造成该区域主要降水的影响系统是高原槽、蒙古槽和高原低涡,若后冬至春季北半球500 hPa极涡中心偏向西(东)半球,青藏高原与我国东部沿海地区高度距平场形成“西低东高(西高东低)”的距平分布型时,海西东部和环青海湖地区容易出现多(少)雪年。Using the grid data of 500 hPa height field which is provided by the Natoinal Climate Center and the ground meteorological observation data of seven meteorological stations over the eastern Haixi and around Qinghai Lake （36°～38°N, 96°～101°E） during 1961--2004, the snow disaster＇s annual table and ground snow sequence is collected, the circulation characteristic of the snow disaster occurred in snowy year and none-snowy year over the eastern Haixi and around Qinghai Lake is analyzed, and based on the climatic diagnosis and the mathematical statistics method the interannual variation characteristic and the generating mechanism as well as the cause of snow disaster are studied. The result shows that the probability of the occurrence of the regional snow disaster over the eastern Haixi and around Qinghai Lake is 15.9% （7/44）, while the probability of the occurrence of the local snow disaster is only 9.1% （4/44）. Among the eleven snow disasters the probability of snow disaster is 91% （ 10/11 ） in later winter to spring （from January to April）, and the probability is 9 % （ 1/11 ） in early winter （from mid October to December）. The slowly increasing of the accumulated snow-cover amount over the eastern Haixi and around Qinghai Lake in winter in the 44 years is prone to snow-cover and low temperature damage. The primary influencing system of precipitation over this region is the plateau trough, Mongolia trough and plateau low cyclone （at the same time accompanying convergence line and shearing line）, i.e., when the 500 hPa polar vortex center of the north hemisphere from winter to spring is leaning against west/east hemisphere, or the height anomaly of Tibetan Plateau and eastern coast region forms into anomaly distribution with ＂low in west but high in east （or high in east but low in east）＂, there has more （only less） snow over the eastern Haixi and around Qinghai Lake. The variation trend of the snow-cover amount in winter and spring in the future 10 years is corre

关 键 词：积雪变化 雪灾 海西东部和环青海湖地区 

分 类 号：P426.635[天文地球—大气科学及气象学] P457.6