Article · Atmosphere · January 3, 2026

Climate-Driven Cryospheric Changes and Their Impacts on Glacier Runoff Dynamics in the Northern Tien Shan

Aigul N. Akzharkynova, Berik A. Iskakov, Gulnara Iskaliyeva, Nurmakhambet Sydyk, Rustam G. Abdrakhimov, Alima Amangeldi

Abstract

Glaciers in the Northern Tien Shan are a major source of Ile River runoff, supplying water to Kazakhstan’s largest city, Almaty. Under ongoing climate warming, their degradation alters the magnitude and seasonality of river discharge, increasing water-resource vulnerability. This study quantifies long-term changes in glacier area, firn-line elevation, and glacier runoff in the northern Tien Shan from 1955 to 2021. The analysis uses multi-decadal meteorological observations, hydrological records, multi-temporal Landsat-7/8 and Sentinel-2 imagery, and DEMs combined with empirical and semi-empirical runoff estimation methods. The glacier area has declined by more than 45–60% since 1955, accompanied by a rise in firn-line altitude from ~3400 to 3700 m. At the Mynzhylky station, mean summer air temperature increased by 0.88 °C, reflecting persistent warming in glacierized elevations. The contribution of glacier meltwater to annual discharge decreased from ~32% in 1955–1990 to ~25% in 1991–2021, while total and vegetation-period runoff increased due to modified seasonal hydrological conditions. These results demonstrate the impact of climate warming on glacier-fed runoff in the Northern Tien Shan and highlight the need to integrate glacier degradation into water-resource management and long-term water-security assessments.

Cryospheric studies and observationsGeology and Paleoclimatology ResearchEnvironmental and Agricultural Sciencesglacier retreatNorthern Tien Shanglacier runoff

Climate-Driven Cryospheric Changes and Their Impacts on Glacier Runoff Dynamics in the Northern Tien Shan

Abstract

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