Energy and mass balance of glaciers in the Ulugh Muztagh driven by climate warming over 44 years

Abstract

Study region

This study focuses on the glaciers of the Ulugh Muztagh region, a remote high-altitude area in the north-central Tibetan Plateau.

Study focus

Using calibrated and downscaled meteorological reanalysis data together with the COSIPY energy and mass balance model, this study systematically investigates the mass balance and energy exchange characteristics of the Ulugh Muztagh glaciers from 1980 to 2023. The analysis covers long-term trends, interannual variability, and the dominant meteorological and glaciological processes affecting glacier change in this region.

New hydrological insights for the region

Results indicate that the mean glacier mass balance was −0.06 ± 0.05 m w.e./yr over the past 44 years, with accelerated mass loss after 2000. Net radiation accounts for 66 % of the glacier energy budget, highlighting its predominant role. July and August are the main ablation months, while accumulation mainly occurs from September to the following March. A significant negative correlation exists between air temperature and glacier mass balance. Snowfall is the major input, and melt is the primary output; notably, sublimation dominates mass loss during the accumulation season. These findings clarify the mechanisms driving glacier change in Ulugh Muztagh and provide critical evidence to assess the region's hydrological response to climate change.