Responses of the Glacier Mass Balance to Climate Change in the Tibetan Plateau During 1975-2013

Approximately 70% of the available water in the entire Tibetan Plateau is stored in glaciers. Understanding the impact of climate change on the glacier mass balance is crucial given that the Plateau is the "water tower" of East and Southeast Asia. However, the historical records of the glacier mass balance for the Tibetan Plateau are scattered and incomplete. In this study, we reconstructed the long-term glacier mass balance from 1975 to 2013 (the data can be downloaded at ) using the field observations for seven major glaciers and corresponding meteorological data extracted from the GLDAS CLSM (Global Land Data Assimilation Systems based on the Catchment Land Surface Model) data set. The effects of refrozen water and snow depth on the glacier mass balance was examined. In addition, the response of glacier mass balance to climate change was investigated. The results indicate that most of the glaciers experienced a mass loss during the study period. Large mass loss occurred in glaciers in the southeastern part of the plateau. The glacier in the northwestern part of the plateau (the Muztagh No.15 Glacier) shows a small mass gain. Regarding the mass components of the glacier mass balance, most mass balances are dominated by meltwater, while the Muztagh No. 15 has a component offset. Further analysis manifests that mass balances in the western glaciers heavily change to the change of moisture factor (precipitation), while for the eastern glaciers, mass balance changes respond strongly to the changes of heat factors (air temperature and net radiation). The differences in the mass balance changes are closely related to the westerlies and Indian summer monsoon.