Recent Indian studies in Himalayan cryosphere

Abstract

Cryosphere all over the globe is thawing, be it the Arctic, Antarctic, Greenland or Himalaya. Studies have predicted that loss in the glacier mass over the Upper Indus Basin in Kashmir Himalaya would amount to 47 to 67% (Romshoo in 7th conference of Science and Geopolitics of Arctic and Antarctic, 2023). A similar trend prevails in the Bhaga basin of the Upper Chenab, where glaciers in size classes < 0.5 km2 and 0.5–1 km2 show a higher relative loss of 25% (0.5% year−1) and 13% (0.3% year−1) respectively (Das et al. in Quat Sci Rev 316:108258; J Mt Sci 20:299–324, 2023). The loss in Eastern Himalaya (Sikkim) has been reported to range from 20 to 30% (Debnath in 7th conference of Science and Geopolitics of Arctic and Antarctic, 2023). On the basis of the compiled records of snout fluctuations of 285 glaciers and two regional means spanning 17 decades from the 1850s, it has been deduced that most of the Himalayan glaciers are retreating, and the retreat rates have accelerated in the past few decades, but the observed tendencies are not regionally uniform (Kulkarni et al. in Water Security 14(6557):100101; J Indian Soc Remote Sensing 49(8):1951–1963, 2021). The excessive ice mass loss has resulted in the formation and/or expansion of glacial melt water lakes posing a threat of Glacial Lake Outburst Flow (GLOF). The results of the studies on the response of climatic variability over the state of cryosphere, the role of debris on the melting of glaciers, changes in the winter precipitation pattern and consequent impact on the hydrological cycle, water availability and state of permafrost over Himalaya have also been a focus of studies, including developing models (Banerjee et al. in Geophys Res Lett 49:096989, 2020), in contemporary publications, enriching the data on the fundamental aspects of glacial processes that are of great societal relevance.