Distribution Characters and Its Control Factors of Stable Isotope in Precipitation over China

The temporal and spatial variations of stable isotope in precipitation over China and its control factors are analyzed based on the observations from IAEA\WMO\GNIP.The results show that the overall stable isotope in precipitation in China has obvious continental and altitude effects.For the Local Meteoric Water Line,the regional differences exist among the studying areas,and there also are obvious differences between winter and summer semi-years at the individual stations of inland area,which reveals the different characters of water vapour mass.The various seasonal variation patterns of stable isotope in precipitation(δ and d-excess) infer that there are different air masses influencing these areas at different seasons.The correlations of long term interannual variations of stable isotope in precipitation with monsoon index and ENSO index interpret that ENSO has an obvious positive relation with the stable isotope,but not always cause the stable isotope variations through the influence on the amount of precipitation.With the emphasis on analyzing the amount and temperature effects,we point out that,the amount of precipitation is the dominative factor in the monsoon areas of China Coast and Southwest China,the temperature is the main factor in the northern territory unaffected by monsoon,and the both effects work together in the intersectant zone.