中国大陆大气降水线斜率分区及其水汽来源研究

Slope zoning of atmospheric precipitation line and its water vapor source in China's Mainland

大气降水是自然界水循环过程中的一个重要环节。由于元素的各个同位素的质量不同,造成了降水中H2O与D2O之间、H2O与H218O之间的分馏效应。水循环过程中,由于同位素成分的热力分馏作用,全球降水中氢和氧稳定同位素存在一种线性关系,1961年Craig把这种关系定义为大气降水线。(Meteoric Water Line,简称为MWL):δD=8δ18O+10,又称为全球大气降水线(Global Meteoric Water Line,简称为GMWL)。本文通过对近年来全国各地大气降水中氢氧稳定同位素(2H、18O)之间的关系的资料进行整合作图,发现大气降水线斜率的大小存在地域差异并具有分区的特征,分析认为这种特征应该与当地降水的水汽来源有着密切联系,结合大气降水水汽来源,将中国大陆降水线斜率大体分为:东南沿海区、西南区、青藏高原区、西北内陆区、东北及华北内陆区几大区域,最终可以通过各地大气降水线的斜率分区来区分不同的水汽来源。

Atmospheric precipitation is an important link in the process of natural water cycle. Due to the different isotopes of each element,the fractionation effect between H2 O and D2 O and between H2 O and H218 O in precipitation has been caused. In the course of water cycle,due to the thermodynamic fractionation of isotopic compositions,there is a linear relationship between hydrogen and oxygen stable isotopes in global precipitation. In 1961,Craig defined this relationship as an atmospheric water line.（ Meteoric Water Line,referred to as MWL） ： also known as the Global Meteoric Water Line（ GMWL）. Based on the atmospheric precipitation across the country in recent years hydrogen stable isotopes（2 H,18 O） the relationship between data mapping,it is found that the slope rainfall line size and area difference with partition characteristics,it is considered that these characteristics should be with the local water sources,water drop is closely related with the precipitation water vapor the source will China,precipitation slope can be divided into： the southeast coastal region,southwest region,Tibetan Plateau area,the inland region,the northeast and North northwest inland region of these areas,can eventually by the local meteoric water line slope partition to distinguish different water sources.