Climatological Significance of δ\u3csup\u3e18\u3c/sup\u3eO in Precipitation and Ice Cores: a Case Study at the Head of the Ürütnqi River, Tien Shan, China
Stable-oxygen-isotope ratios (δ18O) collected from the headwaters of the Ürümqi river, Tien Shan, China, were used to test the relationship between δ18O temporal relationship is found between δ18O monthly averages which remove synoptic-scale influences such as changes in condensation level, condensation temperature and moisture sources (Yao and others, 1996). Linear fits as high as 0.95‰°C-1 for precipitation events and 1.23‰°C-1 for monthly averages are found. Although the δ18O (∼2 km from the precipitation sampling site) decreased dramatically compared to the precipitation samples , the ice-core records of annually averaged δ18O with contemporaneous air temperature, especially summer air temperature, at the nearby Daxigou meteorological station. Nevertheless, the relationship between the ice core δ18O records and contemporaneous air temperature is less significant than that [or the precipitation samples due to depositional and post-depositional modification processes, which are highlighted by the successive snow-pit δ18O No. 1. Our results might extend the application of high-altitude and subtropical ice-core δ18
