Variational features of precipitation δ18O in Northeast Qinghai-Tibet Plateau

There is a marked positive correlation between δO in atmospheric precipitation andtemperature in the Northeast Qinghai-Tihet Plateau.The amount effect in Tuotuohe station is notable as thetemperature is greater than or equal to 7.3℃,so is in Xining as 8.3℃.The analytic results show that thesynoptic and climatic significance of different time scales is different,and their degrees are also different.Moreover,the relations between the weather systems in the Northeast Qinghai-Tibet Plateau and δO inprecipitation are analyzed.Under the influence of continental air mass the δO change in the Plateau issynchronous with that of temperature and under the oceanic air mass originated from the Bengal Bay and theArabian Sea there is a marked negative correlation between δO and precipitation amount or temperature in themonsoon region of the Plateau and also positive one between δO and temperature in the non-monsoon region.