Accumulation Rates over the Past 500 Years Recorded in Ice Cores from the Northern and Southern Tibetan Plateau, China

Abstract

ABSTRACT Based on the Guliya, Dunde, and Dasuopu ice cores and direct observations, we investigated the spatial and temporal variations in precipitation on the Tibetan Plateau over the past 500 yr. The variations in accumulation rates showed significant periodicities of 12.7, 7.6, 6.2, 5.4, 4.4, and 2.1 yr in the Guliya ice core, 9.5, 6.8, 5.7, and 2.1 yr in the Dunde ice core, and 12.3, 7.5, 6.3, 5.3, and 2.4 yr in the Dasuopu ice core. The periodicities displayed in these three ice core records are similar and correspond to the periodicities of the Quasi-Biennial Oscillation, the Southern Oscillation, the North Atlantic Oscillation, and the sunspot cycle. However, the accumulation rate from the Guliya and Dunde ice cores exhibited a generally decreasing trend, while the records from the Dasuopu ice core show a generally increasing trend over the entire period of interest. Our study also indicates that there is a strong negative correlation between the accumulation rates in the ice cores from the northern and southern Tibetan Plateau, especially on climatological (multidecadal or longer) time-scales. Modern meteorological observation data suggest that a dividing line between the northern and southern Tibetan Plateau with respect to variations in precipitation is located at ∼32–33°N. This dividing line coincides with other atmospheric, geographical, geological, and geophysical discontinuities. This suggests that interactions among these phenomena might help to understand the spatial patterns of climate over the Tibetan Plateau.