High-elevation climate changes recorded in Tibetan ice cores and their impact on glacier behavior

Abstract

Glaciers on and around the Tibetan Plateau (TP) have suffered significant mass loss in recent decades. An improved understanding of high-elevation climate conditions will play a crucial role in the assessment of future glacier changes, as large areas of glaciers are located above 5000 m a.s.l. on the TP. In this research, two ice cores retrieved from regions on the TP with different climate regimes were studied to explore climate changes at high elevations from 1942 to 2011 and possible impacts on glacier behavior. The δ18O record of the Kuokuosele ice core from the northwestern TP reveals a general rise in temperature from the 1940s to the 1990s, followed by a decrease at the turn of the century. The precipitation indicated by snow accumulation exhibits a weak drying trend from the 1940s–1970s and a subsequent increase. In the southeastern TP, the temperature at the Zuoqiupu ice core site derived from the CRU TS v4.03 data set indicates a cooling trend between the 1940s and the 1960s, followed by an overall warming until the present. The snow accumulation rate shows an almost inverse relationship to temperature change during the corresponding time periods, increasing briefly in the 1940s–1950s and continuously decreasing since the 1960s. For the glaciers in the northwestern TP with low sensitivity to temperature change, the Karakoram Anomaly since the 1970s can be attributed to the wetting climate and may date to the 1940s. For the maritime glaciers in the southeastern TP, the significant negative mass balance after the 1960s was primarily controlled by climate warming and amplified by decreased precipitation.