天山乌鲁木齐河源1号冰川雪冰中δ^18O的演化过程  

Evolution processes of δ^(18)O in snowpits on No.1 glacier at the Urumqi river head,Tianshan Mountains

作　　者：张明军[1,2] 周平[1] 李忠勤[2,1] 王飞腾[2] 金爽[1] 李瑞雪[1] 

机构地区：[1]西北师范大学地理与环境科学学院,兰州730070 [2]中国科学院寒区旱区环境与工程研究所冰冻圈科学国家重点实验室/天山冰川站,兰州730000

出　　处：《兰州大学学报（自然科学版）》2009年第5期36-40,47,共6页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(40701035,40631001,40571033);霍英东教育基金项目(101019);陇原青年创新人才扶持计划项目;西北师范大学知识与科技创新工程科研骨干培育项目(NWNU-KJCXGC-03-45);西北师范大学自然地理学省级重点学科基金项目;天山冰川观测试验站开展的雪冰现代过程研究项目的一部分

摘　　要：2002年9月14日-2005年3月7日,在天山乌鲁木齐河源1号冰川积累区雪坑中连续观测取样,频率为1次/周,分析了其中的部分表层雪样品和粒雪坑样品中的δ^(18)O。结果表明:表层雪样品的δ^(18)O具有明显的季节变化,且与月平均温度关系密切。粒雪坑样品中的δ^(18)O在9月底至次年6月初变化较小,升华对雪坑1 m以下雪冰中δ^(18)O的影响不超过-2‰,整个雪坑都较好地保持了δ^(18)O的季节变化特征。但6月初-9月底融水对雪冰中δ^(18)O的影响巨大,冬季形成的δ^(18)O低于-30‰的中、细粒雪层,经过夏季融水的改造,可成为δ^(18)O-11.6‰的粗粒雪和冰片层。融水可使雪冰中δ^(18)O的改变量>60%。在全球变暖背景下,冬季形成的低δ^(18)O雪层经过夏季融水的改造,其内的δ^(18)O可以完全被平滑。Analysis of δ^18O in surface snow and snowpit samples collected successively on a monthly basis from September 14, 2002 to March 7, 2005 on the east branch of No.1 glacier at the Urumqi river head, Tianshan Mountain is presented here. δ^18O in surface snow showed obvious seasonal variations, which were associated with the monthly mean temperature. The variations of δ^18O in the snowpits were not obvious from the end of September to the beginning of the next June. The sublimation might have affected δ^18O in the snowpit, but the effect was within -2‰ in the bottom of the snowpit. However, from the beginning of June to the end of September, with the temperature rising, the variations of δ^18O in the snowpits were distinctly caused by melting water. The winter snow layers in which the δ^18O were less than -30‰ could be changed into coarse firn and ice layers in which the δ^18O were more than -11.6% due to the melting water, and the extent of the variations of δ^18O could be more than 60%. With the global warming, the lower δ^18O in the winter snow can be completely smoothed by summer melting water.

关 键 词：雪冰 δ~18O 演化过程 乌鲁木齐河源1号冰川 

分 类 号：P597[天文地球—地球化学]