Tree-ring-inferred glacier mass balance variation in southeastern Tibetan Plateau and its linkage with climate variability

摘要

A large number of glaciers in the Tibetan Plateau (TP) have experiencedwastage in recent decades. And the wastage is different from region toregion, even from glacier to glacier. A better understanding of long-termglacier variations and their linkage with climate variability requiresextending the presently observed records. Here we present the firsttree-ring-based glacier mass balance (MB) reconstruction in the TP, performedat the Hailuogou Glacier in southeastern TP during 1868–2007. Thereconstructed MB is characterized mainly by ablation over the past 140 yr,and typical melting periods occurred in 1910s–1920s, 1930s–1960s,1970s–1980s, and the last 20 yr. After the 1900s, only a few shortperiods (i.e., 1920s–1930s, the 1960s and the late 1980s) were characterizedby accumulation. These variations can be validated by the terminus retreatvelocity of Hailuogou Glacier and the ice-core accumulation rate in Guliyaand respond well to regional and Northern Hemisphere temperature anomaly. Inaddition, the reconstructed MB is significantly and negatively correlatedwith August–September all-India monsoon rainfall (AIR) (r_1871-2008 =−0.342, p < 0.0001). These results suggest that temperature variability isthe dominant factor for the long-term MB variation at the Hailuogou Glacier.Indian summer monsoon precipitation does not affect the MB variation, yet thesignificant negative correlation between the MB and the AIR implies thepositive effect of summer heating of the TP on Indian summer monsoonprecipitation.