南京与西安地区降水同位素的氘盈余和水汽压分析

Analysis of the Influence Factors of Precipitation Isotopes in Nanjing and Xi'an based on Deuterium Surplus and Water Vapor Pressure

在全球大气降水同位素观测网(GNIP)西安和南京站点大气降水氢氧稳定同位素资料的基础上,结合2个地区实际气象数据资料,研究分析了南京和西安地区大气降水稳定同位素的组成,并建立了2个地区大气降水线方程和氘盈余多年月平均变化曲线。通过对比分析,揭示了2个地区大气降水线分布特征的差异性、氘盈余的变化趋势、以及水汽压对大气降水稳定同位素的影响。结果表明:南京地区氘盈余相对西安地区较平稳,变化幅度相对较小;年度尺度上,西安地区大气降水稳定同位素中δD与水汽压成负相关,δ18O与水汽压之间为正相关关系,而南京地区大气降水中氢氧稳定同位素与水汽压皆为负相关关系。

Based on the atmospheric precipitation hydrogen and oxygen stable isotope data of the global at- mospheric precipitation isotope network（GNIP）xi＇an and nanjing site,and combining the actual meteorological data of the two regions.The composition of atmospheric precipitation stable isotopes in nanjing and xi＇an is analyzed, and the curve of atmospheric precipitation line equation and the average change curve of deuterium in the two regions are established.Through comparative analysis, it reveals the differences of the distribution characteristics of the atmospheric precipitation lines in the two regions, the variation trend of deuterium surplus, and the influence of water vapor pressure on the stable isotope of atmospheric precipita- tion.The results show that the deuterium surplus in nanjing is relatively stable in xi＇an area ,and the variation range is relatively small; In the annual scale, the stable isotope 3D of atmospheric precipitation in xi＇an is negatively correlated with water vapor pressure, and there is a positive correlation between 3180 and water vapor pressure.However,the stable isotopes of atmospheric precipitation in nanjing area are nega- tively correlated with water vapor pressure.