The Tien Shan and Pamir mountains host over 28,000 glaciers providing essential water resources for increasing water demand in Central Asia. A disequilibrium between glaciers and climate affects meltwater release to Central Asian rivers, challenging the region's water availability. Previous research has neglected temporal variability. We present glacier mass balance estimates based on transient snowline and geodetic surveys with unprecedented spatiotemporal resolution from 1999/00 to 2017/18. Our results reveal spatiotemporal heterogeneity characterized by two mass balance clusters: (a) positive, low variability, and (b) negative, high variability. This translates into variable glacial meltwater release (≈1–16%) of annual river runoff for two watersheds. Our study reveals more complex climate forcing-runoff responses and importance of glacial meltwater variability for the region than suggested previously.
Bibliographical noteFunding Information:
We thank to the project CICADA (Cryospheric Climate Services for improved Adaptation), with contract no. 81049674 between Swiss Agency for Development and Cooperation and the University of Fribourg. The CAWa (Central Asian Water) project ( http://www.cawa-project.net ) was supported by the German Federal Foreign Office (contract no. AA7090002) as a part of the “Berlin Process.” This study was also supported by the Swiss National Science Foundation (SNSF) by the following two projects: “Snowline observations to remotely derive seasonal to subseasonal glacier mass balance in the Tien Shan and Pamir Mountains,” Grant 155903, and “Changing glacier firn in Central Asia and its impact on glacier mass balance,” Grant 169453. Funding for parts of this work comes from the BMBF (Federal Ministry of Education and Research) research programme PAMIR (FKZ 03G0815) within the CAME (Central Asia and Tibet: Monsoon dynamics and geo‐ecosystems) project. K. Naegeli acknowledges support from the SNSF Mobility Fellowship Grant (P2FRP2/174888). R. McNabb acknowledges support from the European Space Agency through Glaciers_CCI and CCI+ (4000109873/14/I‐NB, 4000127593/19/I‐NS), and by the European Research Council under the European Union's Seventh Framework Programme (FP/2007–2013)/ERC grant agreement no. 320816. E. Barandun acknowledges support from the French Space Agency (CNES). We thank A. Rodriguez Crespo for the proof reading and typesetting of the manuscript. We thank the reviewers and editor of the paper for the constructive reviews that helped to greatly improve the paper.
© 2021. The Authors.
- Tien Shan and Pamir
- annual glacier mass balance time series
- climate change
- hydrological cycle
- transient snowlines