摘要
根据对取自青藏高原东北地区部分降水样中氢氧稳定同位素比率的分析，得到沱沱河站的大气水线（ＭＷＬ）为：δＤ＝８．２５δ１８Ｏ＋９．２２‰，与全球平均ＭＷＬ的差别较小；德令哈、西宁站的ＭＷＬ分别为：δＤ＝５．８６δ１８Ｏ－２７．２８‰和δＤ＝６．９６δ１８Ｏ－３０．１９‰，均与全球平均ＭＷＬ差别较大。这主要归因于水汽源地的非平衡蒸发和凝结物在非饱和大气中降落时的非平衡蒸发。上述地区的过量氘Ｅｘｄ（＝δＤ－８δ１８Ｏ）具有较大的波动范围，并且与δＤ存在显著的正相关关系。说明过量氘在很大程度上受非平衡蒸发过程中氘分馏速率的制约。分析表明，青藏高原东北地区的暖季，来自海洋的水汽具有较低的稳定同位素比率和过量氘；
According to the analyses for the samples from some regions of the Northeast Tibetan Plateau, the meteoric water line of Tuotuohe Station is obtained as δD=8 25δ 18 O+9 22‰, which is similar to that of the globe; MWL of Delingha and Xining Stations are δD=5 86δ 18 O-27 28‰ and δD=6 96δ 18 O-30 19‰ respectively, which are different from that of the globe Excess deuterium (Exd) in the regions mentioned above has great fluctuation, and there is positive relation between Ex d and δD Analyses show that, in the Northeast Tibetan Plateau, the vapor from oceans has low stable isotopic ratio and Exd, and the vapor from the evaporation in the Plateau has high ratio and Exd
出处
《冰川冻土》
CSCD
北大核心
1996年第4期360-365,共6页
Journal of Glaciology and Geocryology
基金
国家攀登计划和国家自然科学基金
关键词
青藏高原
稳定同位素比率
大气水线
过量氘
Tibetan Plateau, stable isotope, excess deuterium, meteoric water line
