山西冬季气温异常的气候特征及成因分析

Climatic Characteristic and Cause Analysis of Winter Temperature Anomaly in Shanxi Province

利用1961-2006年山西省42个测站的气温及NCEP海平面气压场、500 hPa高度场、全球海温资料,采用EOF、合成分析和相关分析方法,分析了山西冬季（12~2月）气温异常的时空特征,并从大气环流和海温两方面分析了气温异常的成因。结果表明,山西冬季气温年代际变化特征明显,1960—1980年代中期为偏冷期;1987年以后至今则持续偏暖,尤其是1990年代后期至2004年,为近46年以来最暖时期。山西冬季气温变暖趋势显著,气候倾向率为0.52℃.（10a）-1,变暖趋势的区域差别不明显。冷、暖冬年大气环流形势差异显著,同期影响因子主要为海平面气压场的西伯利亚高压、河套以西至伊朗以东的500 hPa高度。前期秋季影响因子是副热带的西太平洋、墨西哥湾附近、大西洋的加那利群岛附近及印度的500 hPa高度;前期夏季影响因子是贝加尔湖-河套及以西地区、里海-地中海之间以及北大西洋副热带海区的500 hPa高度。中国东南沿海及日本以南的海温与冬季气温同期相关最好,当这些海区SST为偏暖（冷）时,冬季气温偏暖（冷）。前期秋季北大西洋和印度洋SST特定的型态对冬季气温有明显影响,当秋季这两个海域的海温指数出现暖（冷）异常时,则引起暖（冷）冬。

The temporal and spatial characteristics of winter（from December to February） temperature anomaly in Shanxi Province is analyzed by EOF,synthetic and correlation analysis,using the temperature data at 42 stations in Shanxi Province,NCEP sea level pressure,500 hPa height and the SST of global from 1961 to 2006.And its cause is analyzed from atmospheric circulation and SST.The results show that the decadal variation of temperature in winter is obvious,there is cold period from 1960s to mid 1880s,and a warm period after 1987,especially,the late 1990s to 2004,is the warmest period for the past 46 years.There is a sharp rising trend of winter temperature in Shanxi Province,and climate trend rate is 0.52℃·（10a）-1,while slight regional differences.The regional difference of warming trend is no obvious.The atmospheric circulation in cold and warm winters is significant.The key regions are the Siberia in sea level pressure field,and 500 hPa height in west Loop to east Iran.The impact factors of preceding-autumn are the 500 hPa height in western Pacific,near the Gulf of Mexico,the Canary islands and India of subtropical;the impact factors of preceding-summer are 500 hPa height in west of Tony Lake Loop,Caspian Sea Mediterranean,and the North Atlantic of subtropical.SST of southeast coast of China and south of Japan,and SST at the same period are closely related to the temperature anomaly in winter of Shanxi Province.When the SSTs above areas are warmer（colder）,the temperature warmer（colder） in winter.There is a good correlation between the SST of the North Atlantic and Indian Ocean in the early autumn and the winter temperature.When the SST is warmer（colder）,the temperature is warmer（colder） in winter.