delta 18O records in water vapor and an ice core from the eastern Pamir Plateau: Implications for paleoclimate reconstructions

This study is the first to examine delta 18O in daily water vapor at Taxkorgan on the eastern Pamir Plateau. The results show that changes in observed and simulated delta 18O values in water vapor/precipitation at the event scale (using a LMDZ-iso model) were mainly affected by temperature. The influences of humidity, precipitation amount, and different moisture sources, such as the westerlies, local evaporated moisture, and polar air masses, on delta 18O values are comparatively weak. The combination of the delta 18O record from the Muztagata ice core, 58 km away from the study area, and the LMDZ-iso simulated annual delta 18O pattern in precipitation at Taxkorgan also demonstrated that temperature, and particularly the temperature of the regions over which the southern branch of the westerlies flows, is the most important factor controlling delta 18O variations. The results from this study area, which is dominated by the westerlies throughout the year, are markedly different from those derived from parts of the Tibetan Plateau that are dominated by the combined influences of the westerlies in winter and the Indian monsoon in summer. The results suggested that the eastern Pamir Plateau is an ideal location to reconstruct past temperature variations and that the delta 18O records preserved in ice cores from the region are a suitable and robust proxy for temperature.