The altitude effect of δ18O in precipitation and river water in the Southern Himalayas
The altitude effect of δ18O in precipitation and river water in the Southern Himalayas
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DOI：
10.1007/s11434-012-4992-7
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发表时间：
2012-03
影响因子：
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通讯作者：
R. Wen;L. Tian;Y. Weng;Zhongfang Liu;Zhongping Zhao
中科院分区：
文献类型：
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作者：
R. Wen;L. Tian;Y. Weng;Zhongfang Liu;Zhongping Zhao
水同位素的消失率可用于研究青藏高原的水循环和估算青藏高原的隆升。南喜马拉雅山脉的海拔对比较大，这使得对这一延迟率的详细讨论成为可能。分析了南喜马拉雅海拔1320m~6700m范围内降水和河水中δ18O的变化，并计算了水体δ18O的比递减率。结果表明，该地区降水多年平均递减率为0.15‰/100m，南喜马拉雅地区3个站点的年平均递减率为0.17‰/100m。这两个结果是一致的，但远低于全球平均值0.28‰/100m。这项工作还表明，季风季和非季风季的降水δ18O递减率存在差异。计算的降水递减率远低于地表水。
The lapse rate of water isotopes is used in the study of the hydrologic cycle as well as in the estimation of uplift of the Tibetan Plateau. The greater elevation contrast in the Southern Himalayas allows for a detailed discussion about this lapse rate. We analyze variations ofδ18O in precipitation and river water between 1320 m and 6700 m elevations in the Southern Himalayas, and calculate the specific lapse rate of waterδ18O. The results show that the multi-year average lapse rate in precipitation over this region is 0.15‰/100 m. The one-year average lapse rate is 0.17‰/100 m from three sites along the Southern Himalayas. The two results agree, but are much lower than the global average of 0.28‰/100 m. This work also shows that there is a difference in precipitationδ18O lapse rate between the monsoon and non-monsoon seasons. The calculated precipitation lapse rate is much lower than that in surface water.