Abstract. The importance of updated knowledge about the glacier extent and characteristics in the Himalaya cannot be overemphasized. Availability of precise glacier inventories in the latitudinally diverse western Himalayan region is particularly crucial. In this study we have created an inventory of the Suru sub-basin in the western Himalaya for the year 2017 using Landsat Operational Land Imager (OLI) data. Changes in glacier parameters have also been monitored from 1971 to 2017 using temporal satellite remote-sensing data and limited field observations. Inventory data show that the sub-basin has 252 glaciers covering 11 % of the basin, having an average slope of 25±6∘ (standard deviations have been italicized throughout the text) and dominantly north orientation. The average snow line altitude (SLA) of the basin is 5011±54 m a.s.l. with smaller (47 %) and cleaner (43 %) glaciers occupying the bulk area. Long-term climate data (1901–2017) show an increase in the mean annual temperature (Tmax⁡ and Tmin⁡) of 0.77 ∘C (0.25 and 1.3 ∘C) in the sub-basin, driving the overall glacier variability in the region. Temporal analysis reveals a glacier shrinkage of ∼6±0.02 %, an average retreat rate of 4.3±1.02 m a−1, debris increase of 62 % and a 22±60 m SLA increase in the past 46 years. This confirms their transitional response between the Karakoram and the Greater Himalayan Range (GHR) glaciers. Besides, glaciers in the sub-basin occupy two major ranges, the GHR and Ladakh Range (LR), and experience local climate variability, with the GHR glaciers exhibiting a warmer and wetter climate as compared to the LR glaciers. This variability manifests itself in the varied response of GHR and LR glaciers. While the GHR glaciers exhibit an overall rise in SLA (GHR: 49±69 m; LR: decrease of 18±50 m), the LR glaciers have deglaciated more (LR: 7 %; GHR: 6 %) with an enhanced accumulation of debris cover (LR: 73 %; GHR: 59 %). Inferences from this study reveal prevalence of glacier disintegration and overall degeneration, transition of clean ice to partially debris-covered glaciers, local climate variability and non-climatic (topographic and morphometric)-factor-induced heterogeneity in glacier response as the major processes operating in this region. The Shukla et al. (2019) dataset is accessible at https://doi.org/10.1594/PANGAEA.904131.

Abstract. Updated knowledge about the glacier extent and characteristics in the Himalaya cannot be overemphasised. Availability of precise glacier inventories in the latitudinally diverse western Himalayan region is particularly crucial. In this study we have created an inventory of the Suru sub-basin, western Himalaya for year 2017 using Landsat OLI data. Changes in glacier parameters have also been monitored from 1971 to 2017 using temporal satellite remote sensing data and limited field observations. Inventory data shows that the sub-basin has 252 glaciers covering 11 % of the basin, having an average slope of 25 ± 6° and dominantly north orientation. The average snow line altitude (SLA) of the basin is 5011 ± 54 masl with smaller (47 %) and cleaner (43 %) glaciers occupying the bulk area. Longterm climate data (1901–2017) shows an increase in the mean annual temperature (Tmin & Tmax) by 0.77 ºC (0.25 & 1.3 ºC) in the sub-basin, driving the overall glacier variability in the region. Temporal analysis reveals a glacier shrinkage of ~ 6 ± 0.02 %, an average retreat rate of 4.3 ± 1.02 ma−1, debris increase of 62 % and 22 ± 60 m SLA rise in past 46 years. This confirms their transitional response between the Karakoram and the Greater Himalayan Range (GHR) glaciers. Besides, glaciers in the sub-basin occupy two major ranges, i.e., GHR and Ladakh range (LR) and experience local climate variability, with the GHR glaciers exhibiting a warmer and wetter climate as compared to the LR glaciers. This variability manifestes itself in the varied response of GHR and LR glaciers. While the GHR glaciers exhibit an overall rise in SLA (GHR: 49 ± 69 m; LR: decrease by 18 ± 50 m), the LR glaciers have deglaciated more (LR: 7 %; GHR: 6 %) with an enhanced accumulation of debris cover (LR: 73 %; GHR: 59 %). Inferences from this study reveal prevalence of glacier disintegration and overall degeneration, transition of clean ice to partially debris covered glaciers, local climate variability and non-climatic (topographic and morphometric) factor induced heterogeinty in glacier response as the major processes operatives in this region. The dataset (Shukla et al., 2019) is accessible at https://doi.pangaea.de/10.1594/PANGAEA.904131.

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This study investigates stagnation conditions of the Pensilungpa glacier, western Himalaya. Multiple glacier parameters (length, area, debris extent and thickness, snowline altitude (SLA), velocity, downwasting and ice cliffs) were studied using field measurements (2016–18), high-resolution imagery from GoogleEarth (2013–17) and spaceborne Landsat, ASTER and SRTM data (1993–2017) to comprehend the glacier's current state. Results show a moderate decrease in length (6.62 ± 2.11 m a−1) and area (0.11 ± 0.03% a−1), a marked increase in SLA (~6 m a−1) and debris cover (2.86 ± 0.29% a−1) and a slowdown of ~50% during 1993–2016. Notable thinning of −0.88 ± 0.04 m a−1 was observed between 2000 and 2017 showing a similar trend as field measurements during 2016–17 (−0.88 m) and 2017–18 (−1.54 m). Further, results reveal a stagnation of the lower ablation zone (LAZ). Less mass supply and heterogeneous debris growth (6.67 ± 0.41% a−1) over the previous decade resulted in slowdown, margin insulation and slope-inversion, leading to stagnation. Stagnation of LAZ caused bulging in the dynamic upper ablation zone and favored the development of supraglacial ponds and ice cliffs. Ice cliffs have grown significantly (48% in number; 41% in area during 2013–17) and their back-wasting now dominates the ablation process.