我国东北地区大气降水稳定同位素特征及其水汽来源

依据全球大气降水同位素观测网络(GNIP)中我国东北地区的月大气降水氢氧稳定同位素资料,并结合相关气象资料,分析了该地区大气降水稳定同位素时空分布特征及其影响因子,并建立了局地大气水线方程.结果表明,东北地区大气降水中δ18O值总体上较低,在时间变化上,表现为冬低夏高;从空间分布来看,由南至北加权平均δ18O值呈减小趋势;降水δ18O与温度线性关系显著,而与降水量则不存在线性关系,利用降水δ18O与温度、降水量、高程、经度和纬度等气候因子建立的多元线性回归关系可以对降水δ18O进行定量估算;采用HYSPLIT 4.9模型对GNIP观测点水汽来源进行追踪,气团聚类轨迹表明,该区全年有两条水汽路径,分别为西风带输送的大西洋、极地北冰洋冷湿水汽和太平洋暖湿水汽.

Characteristics of Stable Isotopes in Precipitation over Northeast China and Its Water Vapor Sources

Based on the data of the hydrogen and oxygen stable isotopes in precipitation over Northeast China provided by the Global Network of Isotopes in Precipitation(GNIP) and the meteorological statistics,the spatial and temporal variations of stable isotopes in precipitation and their influencing factors were analyzed and the Local Meteoric Water Line(LMWL) was established.The results were as follows: δ18 O value was low in winter and high in summer;the spatial distribution showed that the weighted δ18 O value decreased from the south to the north;the linear relationship between δ18 O in precipitation and temperature was significant,but no linear relationship was found for the precipitation amount;δ18 O in precipitation can be evaluated quantitatively based on a multiple linear regression equation with δ18 O and related parameters(temperature,precipitation amount,elevation,longitude and latitude).The water vapor source of the sampling sites was tracked by HYSPLIT 4.9 model,and the modeled trajectory of vapor source indicated that there were two main paths,including the cold wet water vapor from the Atlantic Ocean and the Arctic Ocean via Westerlies,and the warm one from the Pacific Ocean.