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2005年10-11月中美联合考察队在各拉丹冬峰北部果曲冰川平坦的粒雪盆(33o34’37.8“N,91o10’35.3”E,5720m a.s.l.)钻取了一支冰芯,通过对该冰芯进行多参数定年,恢复了青藏高原中部各拉丹冬地区近70年来降水中δ18O的变化历史。根据冰芯中季风期和非季风期δ18O值与临近气象台站气温的正相关性,重建了该地区70年来的春季和夏季的气温变化。结果表明,各拉丹冬冰芯中δ18O记录的春季和夏季升温趋势非常明显;根据回归分析,冰芯中非季风期的δ18O每增大(或减小)1‰相当于春季气温升高(或降低)1.3oC;季风期的δ18O每增大(或减小)1‰相当于夏季气温升高(或降低)0.4oC;各拉丹冬冰芯中δ18O记录恢复的春季和夏季气温与北半球春季和夏季的气温变化具有一致的趋势,但各拉丹冬地区的增温幅度比北半球要大,同时春季的增温幅度也高于夏季。
From October to November 2005, the Sino-U.S. Joint Expedition Drilled a piece of ice from the flat ice-snow basin of the Gojiqu glacier in northern Lhasa Dongtung (33o34’37.8 “N, 91o10’35.3” "E, 5720m asl) According to the multi-parameter dating of the ice core, the change history of δ18O in precipitation over the past 70 years in the central Tibetan Plateau was restored. Based on the positive correlation between the δ18O values in monsoon and non-monsoon periods and the temperatures in adjacent meteorological stations in ice cores, the temperature changes in spring and summer in the past 70 years have been reconstructed. The results show that δ18O recorded in each bindenone ice core shows an obvious trend of warming in spring and summer. According to regression analysis, every increase (or decrease) of δ18O in non-monsoon phase in ice core is equivalent to an increase in spring temperature ( Or decreased) 1.3oC. The increase or decrease of δ18O in monsoon period was 1 ‰, which was equivalent to 0.4oC in summer (or decreased) in summer. The spring and summer temperatures recovered from δ18O records in ice cores of each Ludan winter were similar to those in the northern hemisphere The temperature changes in spring and summer are in a consistent trend, but the warming rate in each region is greater than that in the northern hemisphere, and the warming rate in spring is also higher than that in summer.