Seven-decade of mass balance change in selected large Himalayan and Karakoram glaciers: Climatic drivers and regional contrasts

We reconstructed glacier-wide mass balance (MB) for five large glaciers (area ≥ 100 km²) across the Karakoram and Himalaya from 1950 to 2022 using a temperature-index model, calibrated with geodetic MBs (2000–2019) and validated against independent MB estimates. Mean annual MBs ranged from near equilibrium in the Karakoram (≈0.01 m w.e. a⁻ˡ for Baltoro and Siachen) to substantial losses in the Himalaya (−0.22 to −0.83 m w.e. a⁻ˡ for Bara Shigri, Gangotri, and Zemu). Mass turnover was low in the Karakoram (0.08–0.18 m w.e. a⁻ˡ) and considerably higher in the Himalaya (0.58–0.94 m w.e. a⁻ˡ). MB of Karakoram glaciers (Baltoro, Siachen) is primarily controlled by summer snowfall and summer temperature, Himalayan glaciers (Bara Shigri, Gangotri) by winter snowfall and summer temperature, and Zemu Glacier by winter snowfall and both summer and winter temperatures. Sensitivity to climatic forcing was significantly higher in the Himalaya than in Karakoram. All glaciers exhibited accelerated mass loss after 2000 (≈17–267%), coincident with rising temperatures and declining precipitation, demonstrating strong regional contrasts in glacier–climate interactions.