VARIATIONAL FEATURES OF PRECIPITATION DELTA-O-18 IN NORTHEAST QINGHAI-TIBET PLATEAU

There is a marked positive correlation between delta(18)O in atmospher ic precipitation and temperature in the Northeast Qinghai-Tibet Platea u. The amount effect in Tuotuohe station is notable as the temperature is greater than or equal to 7.3 degrees C, so is in Xining as 8.3 deg rees C. The analytic results show that the synoptic and climatic signi ficant of different time scales is different, and their degrees are al so different. Moreover, the relations between the weather systems in t he Northeast Qinghai-Tibet Plateau and delta(18)O in precipitation are analyzed. Under the influence of continental air mass the delta(18)O change in the Plateau is synchronous with that of temperature and unde r the oceanic air mass originated from the Bengal Bay and the Arabian Sea there is a marked negative correlation between delta(18)O and prec ipitation amount or temperature in the monsoon region of the Plateau a nd also positive one between delta(18)O and temperature in the non-mon soon region.