湖南长沙地区大气降水中稳定同位素特征变化

根据2010年1月~2011年2月长沙地区日降水中δD、δ18O资料,分析了该地区天气尺度下降水中δD、δ18O变化特征。结果表明:在天气尺度下长沙地区大气降水中δ18O与降水量、水汽压、温度及相对湿度之间存在显著的负相关关系,表明该地区降水中δ18O的变化具有显著的降水量效应、湿度效应及反温度效应。长沙地区的大气降水线为:δD=8.38δ18O+173〖WTBZ〗,该方程与GNIP（Globe Network of Isotopes in Precipitation）提供的长沙在月尺度下所得到的大气水线方程的斜率和截距相近,但斜率和截距都比GMWL(Globe Meteoric Water Line)偏大,说明该地区具有湿润多雨的气候特点。研究结果对揭示东亚季风区稳定同位素变化特征以及古气候的解释具有重要意义

VARIATIONS OF STABLE ISOTOPIC CHARACTERISTICS OF ATMOSPHERIC PRECIPITATION FROM CHANGSHA,HUNAN

Based on the data of daily δD,δ18O of precipitation in Changsha station from Jan.2010 to Feb.2011.we have analyzed the variable characteristics of δD,δ18O of precipitation under the synoptic timescale.The results indicated that there was significantly negative correlation of δ18O in precipitation with precipitation amount,vapor pressure,temperature and relative humidity under the synoptic in Changsha,and the variation of δ18O in precipitation had significant precipitation amount effect,humidity effect and anti-temperature effect.The meteoric water line was δD=8.38δ18O+17.3 in Changsha,which was similar to the line under the monthly timescale according to GNIP(Globe Network of Isotopes in Precipitation).But the slope and intercept of Changsha was larger than GMWL(Globe Meteoric Water Line),which revealed that it had the climatic characteristics of humid and rainy in Changsha.These results had great impacts on revealing stable isotopic characteristics in East Asian monsoon and interpreting pale climate studies.