西藏浅层地温对气候变暖的响应  

Response of Shallow Geotemperature to Climatic Change over Tibet from 1971 to 2005

作　　者：杜军[1] 胡军 罗布次仁 周保琴 路红亚[1] 

机构地区：[1]西藏自治区气候中心,西藏拉萨850001 [2]拉萨市气象局,西藏拉萨850001 [3]西藏自治区气象台,西藏拉萨850001 [4]西藏自治区林芝地区气象局,西藏林芝860001

出　　处：《冰川冻土》2008年第5期745-751,共7页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(40565002)资助

摘　　要：利用1971—2006年西藏13个站的0～20cm浅层地温资料，采用气候倾向率等现代统计诊断方法，研究了近36a来西藏年、季平均地温的变化趋势及气候突变．结果表明：西藏地表年平均地温绝大部分站点呈现显著的升高趋势，升幅为0．26～0．91℃·（10a）^-1，以狮泉河升幅最大．夏季10cm平均地温，改则以-0．28℃·（10a）^-1的速率降低，其它各站升幅为0．08～0．79℃·（10a）^-1，以江孜增温幅度最突出．冬季10cm平均地温除林芝变化趋势不大外，其它各站均呈现显著的升温趋势．就西藏平均而言，年、季平均浅层地温表现为显著的升高趋势，其中冬季增幅最大，夏季最小．绝大部分站点年、季浅层平均地温较同时期的平均气温增温幅度更明显，年平均地温呈逐年代升高趋势，20世纪70年代偏低，90年代偏高．昌都地区北部、林芝地区、泽当和日喀则年、季浅层地温从未发生突变，其它大部分站点浅层年平均地温突变时间都发生在20世纪80年代中后期．The changing tendency and abrupt change of annual and seasonal mean shallow geotemperatures over Tibet Region are investigated in this paper with the observational data from 13 stations during the period of 1971-2006 using modern statistical diagnostic methods, such as the linear trend analysis. The results show that the increasing tendency of annual mean geotemperature at surface can be seen in the most stations in the region, with an increasing rate of 0.26-0.91 ℃·（10a）^-1 （99% confidence level）, especially in Senggecangbu. In summer, the mean geotemperature at 10 cm deep had decreased in Gertse County, with a decreasing rate of 0.28 ℃ · （10a）^-1, however, it had significantly increased in other stations, with an increasing rate of 0.08-0. 79 ℃ · （10a）^-1 , and reaching a maximum in Gyantse. In winter, the variation of mean geotemperature at 10 cm deep was no obvious in Nyingtri, but a significant increase occurred in other stations. Also, in terms of average over Tibet, the seasonal and annual mean shallow geotemperatures increased significantly, the increasing rate had a maximum in winter and a minimum in summer. Compared with air temperature, the rising range of annual and seasonal shallow geotemperatures was larger in the most stations of Tibet in the same period, and the decadal variation of the annual mean geotemperature had increased apparently too. The geotemperature was lower in the 1970s, normal in the 1980s and higher in the 1990s. The annual and seasonal mean geotemperatures had no abrupt change in northern Qamdo Prefecture, Nyingtri Prefecture, Tesdang County and Shigatse County, but the abrupt change occurred in the other stations of Tibet in middle-end of the 1980s, indicating a shift from the colder to the warmer.

关 键 词：浅层地温 变化趋势 突变 西藏高原 

分 类 号：P463.23[天文地球—大气科学及气象学]