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

J Duan,L Li,Y Sun,L Wang

doi:10.5194/cp-9-2451-2013

Abstract

Abstract. A large number of glaciers in the Tibetan Plateau (TP) have experienced wastage in recent decades. And the wastage is different from region to region, even from glacier to glacier. A better understanding of long-term glacier variations and their linkage with climate variability requires extending the presently observed records. Here we present the first tree-ring-based glacier mass balance (MB) reconstruction in the TP, performed at the Hailuogou Glacier in southeastern TP during 1868–2007. The reconstructed 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 short periods (i.e., 1920s–1930s, the 1960s and the late 1980s) were characterized by accumulation. These variations can be validated by the terminus retreat velocity of Hailuogou Glacier and the ice-core accumulation rate in Guliya and respond well to regional and Northern Hemisphere temperature anomaly. In addition, the reconstructed MB is significantly and negatively correlated with August–September all-India monsoon rainfall (AIR) (r1871-2008 = −0.342, p < 0.0001). These results suggest that temperature variability is the dominant factor for the long-term MB variation at the Hailuogou Glacier. Indian summer monsoon precipitation does not affect the MB variation, yet the significant negative correlation between the MB and the AIR implies the positive effect of summer heating of the TP on Indian summer monsoon precipitation.

Highlights

Increased glacier melting as a result of climate warming has occurred in many glaciers worldwide in recent decades (Jansen et al, 2007), which has led to sea-level rise in some regions and has affected large-scale hydrological and atmospheric circulation (Jacob et al, 2012; Yao et al, 2007; Liu et al, 2012), and has threatened human safety (Bury et al, 2011)
Correlation analysis displayed that the mean latewood density (MLD) residual chronology was significantly and negatively correlated with the mass balance (MB) over the common period 1960–1993 (r = −0.573, p < 0.001), and the highest correlation occurred in the period 1960–1990 (r = −0.646, p < 0.001)
The significant negative correlation between the MLD and the MB suggested that the mean latewood density of Abies fabri could be a useful indicator of the MB variation at the Hailuogou Glacier, and implied inverse response of the two parameters to the climate condition in the study region determined by different processes

Summary

Introduction

Increased glacier melting as a result of climate warming has occurred in many glaciers worldwide in recent decades (Jansen et al, 2007), which has led to sea-level rise in some regions and has affected large-scale hydrological and atmospheric circulation (Jacob et al, 2012; Yao et al, 2007; Liu et al, 2012), and has threatened human safety (Bury et al, 2011). Wastage is different from region to region, even from glacier to glacier due to spatially heterogeneous response of glacier variation to climate change (Yao et al, 2012; Fujita and Nuimura, 2011; Scherler et al, 2011). Understanding of the long-term response of glacier variation to climate change is limited by the length of observed glacier records and sparse ice-core materials, especially for the southeastern TP, where the observed glacier record is scarce and short while ice-core materials have not yet been obtained owing to complex topography. Tree rings from glacial regions could be a good proxy for long-term glacier variation studying (Bräuning, 2006; Xu et al, 2012), especially for the high-resolution reconstruction of mass balance (MB) (Lewis and Smith, 2004; Watson and Luckman, 2004; Linderholm et al, 2007).

Methods

Results

Conclusion