Tree-ring perspective on past and future mass balance of the glaciers in Tien Shan (Central Asia): An example from the accumulation area of Tuyuksu Glacier, Kazakhstan

The Tien Shan glaciers, known as “Central Asia's Water Tower,” have a direct influence on water resource management in downstream parched areas. The limited time periods of currently available observational climate datasets hamper an accurate examination of glacial changes in Central Asia in terms of long-term climate change implications. In this work, we analysed this change by combining tree-ring-based reconstructions of the accumulation area of the Tuyuksu Glacier during the last 382 years with models of the future mass balance of this glacier until the year 2100 CE. The results show that mountain precipitation is an important force driving the cycles of the cryosphere, biosphere and hydrosphere in arid Central Asia. This driving force has broad coherence in spatiotemporal variation, with periodic cycles and decadal shifts caused by the North Atlantic Oscillation and the El Niño-Southern Oscillation. The multi-model mean in CMIP6 suggests a downward trend in glacier mass balance until 2100, but this trend will be moderated by increased precipitation. The findings of the study could help to explain how the glacial mass balance has evolved in the Tien Shan Mountains of Central Asia throughout time and its relationship to biosphere and hydrosphere.