@article{20971, abstract = {Mountain glaciers are among the natural systems most vulnerable to climate change. However, their interactions with the atmosphere are complex and not fully understood. These interactions can trigger rapid adjustments and climate feedbacks that either amplify or attenuate atmospheric signals, influencing both glacier response and large-scale atmospheric circulation. Observing this functional coupling in nature is challenging because the key processes occur over a wide range of spatial and temporal scales. However, recent advances in observational techniques and modeling have provided new insights into these interactions. In this review, we summarize the current state of knowledge on glacier-atmosphere interactions in high-mountain regions at different scales, and highlight recent advances in observational and numerical modeling. We also highlight important knowledge gaps and outline future research directions to improve the prediction of glacier change in a warming world.}, author = {Sauter, T. and Brock, B. W. and Collier, E. and Goger, B. and Groos, A. R. and Haualand, K. F. and Mott, R. and Nicholson, L. and Prinz, R. and Shaw, Thomas and Stiperski, I. and Georgi, A. and Haugeneder, M. and Mandal, A. and Reynolds, D. and Saigger, M. and Sicart, J. E. and Voordendag, A.}, issn = {1944-9208}, journal = {Reviews of Geophysics}, number = {1}, title = {{Glacier-atmosphere interactions and feedbacks in high-mountain regions - A review}}, doi = {10.1029/2024RG000869}, volume = {64}, year = {2026}, } @article{21406, abstract = {This preliminary study investigates the trace-element composition of ostracod shells (Ostracoda: Crustacea) as biogenic calcium carbonates in their role as environmental sentinels of pollution. Using high-resolution in-situ analysis, we compared two contrasting coastal systems: the highly urbanized seascape of metropolitan megacity Hong Kong (HKSAR) and the agriculturally dominated waters of rural retreat Jeju Island, Republic of Korea (ROK). The goal was to assess whether anthropogenic stress gradients affect trace element-to‑calcium ratios (E/Ca) in the carapaces of shallow-marine Neonesidea Maddocks, 1969 species. Hereby, the focus is laid on potential differences in the effects of extreme urbanization and extreme agriculturalization. We analyzed 12 trace elements commonly incorporated into ostracod shells using Inductively Coupled Plasma–Mass Spectrometry (ICP-MS). Only Mn/Ca, Mg/Ca, and Ni/Ca ratios showed strong correlations with specific seawater physicochemical parameters. Notably, Mn/Ca differed significantly between the two sites, seemingly driven mainly by variations in nitrite nitrogen levels. This suggests that Mn incorporation is sensitive to pollution source, urban versus agricultural, though species-specific uptake effects cannot be excluded. No significant differences in elemental uptake were found between adult and A-1 juvenile stages of Neonesidea mutsuensis Ishizaki, 1961 or Neonesidea elegans (Brady, 1969), supporting the use of both age groups in environmental reconstructions and increasing potential sample yields. While remaining empirical and exploratory, our tentative findings suggest that ostracod geochemistry holds promise for marine pollution monitoring and cautiously supports the application of ostracod Mn/Ca ratios to reconstruct anthropogenic, particularly nitrogen-related, impacts in nearshore environments using sediment core records.}, author = {Jöst, Anna B. and Rodriguez Moreno, Maximiliano J and Kim, Taihun and Baker, David M. and Yasuhara, Moriaki and Not, Christelle A. and Karanovic, Ivana}, issn = {1879-3363}, journal = {Marine Pollution Bulletin}, number = {6}, publisher = {Elsevier}, title = {{Ostracod shell chemistry as proxy for coastal marine conditions of a highly urbanized megacity (Hong Kong SAR) and an agro-centric oceanic province (Jeju Island, Republic of Korea) – a preliminary comparative analysis}}, doi = {10.1016/j.marpolbul.2026.119493}, volume = {227}, year = {2026}, } @article{21454, abstract = {This study examines the distribution, growth, and GLOF hazard of glacial lakes across major Himalayan river basins. Basin-wise GLOF susceptibility was assessed using glacial lake abundance, spatial distribution, and rates of lake area expansion. The Kosi, Yarlung Zangbo, Manas, and Upper Indus basins were identified as the most susceptible and classified as critical. The highest rates of lake size increase were observed in the Kosi Basin, followed by Yarlung Zangbo, Manas, Karnali, Upper Indus, and Tista, indicating their potential as future GLOF-prone regions. Moreover, a Himalayan-scale GLOF hazard map was generated integrating population, hydropower infrastructure, potential flood volume, roads, settlements, and railways revealing high hazard levels in the Chenab, Jhelum, Teesta, and Beas basins in India; the Koshi, Tama-Koshi, and Dudh-Koshi basins in Nepal; and the Kuri Chu sub-basin of the Manas Basin in Bhutan. These findings highlight priority regions where detailed field investigations and hydrodynamic modelling are essential before further infrastructure development.}, author = {Mohanty, Litan and Gantayat, Prateek}, issn = {1947-5713}, journal = {Geomatics Natural Hazards and Risk}, number = {1}, publisher = {Taylor & Francis}, title = {{Comprehensive assessment of Himalayan glacial lakes concerning their distribution, dynamics, and hazard potential}}, doi = {10.1080/19475705.2026.2639085}, volume = {17}, year = {2026}, } @article{21708, abstract = {On October 4, 2023, a proglacial lake named the South Lhonak lake was the source of a catastrophic Glacier Lake Outburst Flood (GLOF) in the Teesta river basin area, resulting in 24 fatalities and leaving over 70 persons missing. The GLOF also destroyed 13 bridges and a major hydropower plant in the Chungthang region. Over 60,000 individuals in four districts of Sikkim were impacted by this GLOF event. This study examines the factors that led to the GLOF event. Our study shows that the cause of this GLOF was initiated by a landslide, that dumped a substantial amount (~ 38.31 million m3) of debris into the South Lhonak Lake. Furthermore, the glacier that was connected to the lake, lost a big chunk of ice mass (~ 7 million m3) due to calving. The combination of these two processes led to the collapse of the left lateral moraine that consequently generated flood waves which breached the terminal moraine dam of the lake. We recommend monitoring land subsidence and calving events for large proglacial lakes to prevent the disastrous consequences of such GLOFs in the future.}, author = {Mohanty, Litan Kumar and Gantayat, Prateek and Dixit, Ankur and Das Adhikari, Manik and Biswas, Rahul and Singh, Vivek Kumar}, issn = {2045-2322}, journal = {Scientific Reports}, publisher = {Springer Nature}, title = {{Sequence of events that led to the South Lhonak lake outburst flood in Sikkim, India}}, doi = {10.1038/s41598-026-35895-7}, volume = {16}, year = {2026}, } @article{19777, abstract = {Snow cover is of key importance for water resources in high mountain Asia (HMA) and is expected to undergo extensive changes in a warming climate. Past studies have quantified snow cover changes with satellite products of relatively low spatial resolution (∼500 m) which are hindered by the steep topography of this mountain region. We derive snowlines from Sentinel-2 and Landsat 5, 7 and 8 images, which, thanks to their higher spatial resolution, are less sensitive to the local topography. We calculate the snow line altitude (SLA) and its seasonality for all glacierized catchments of HMA and link these patterns to climate variables corrected for topographic biases. As such, the snowline changes provide a clear proxy for climatic changes. Our results highlight a strong spatial variability in mean SLA and in its seasonal changes, including across mountain chains and between the monsoon-dominated and the westerlies-dominated catchments. Over the period 1999–2019, the western regions of HMA (Pamir, Karakoram, Western Himalaya) have undergone increased snow coverage, expressed as seasonal SLA decrease, in spring and summer. This change is opposed to a widespread increase in SLA in autumn across the region, and especially the southeastern regions of HMA (Nyainqentanglha, Hengduan Shan, South–East Himalaya). Our results indicate that the diversity of seasonal snow dynamics across the region is controlled not by temperature or precipitation directly but by the timing and partitioning of solid precipitation. Decadal snowline changes (1999–2009 vs 2009–2019) seasonally precede temperature changes, suggesting that seasonal temperature changes in the Karakoram–Pamir and Eastern Nyainqentanglha regions may have responded to snow cover changes, rather than driving them.}, author = {Bernat, M. and Miles, E. S. and Kneib, M. and Fujita, K. and Sasaki, O. and Shaw, Thomas and Pellicciotti, Francesca}, issn = {1748-9326}, journal = {Environmental Research Letters}, number = {6}, publisher = {IOP Publishing}, title = {{Precipitation phase drives seasonal and decadal snowline changes in high mountain Asia}}, doi = {10.1088/1748-9326/adcf39}, volume = {20}, year = {2025}, } @misc{19780, abstract = {This repository contains the data used for the study Precipitation phase drives seasonal and decadal snowline changes in high mountain Asia. This study focuses on 4776 glacierized catchments across high mountain Asia (HMA). They are numbered from 0 to 4775. This code number is then used in all the products as their unique ID. }, author = {Bernat, M}, publisher = {Zenodo}, title = {{Snow line altitude in high mountain Asia derived from satellite imagery (LS5, LS7, LS8 & S2) between 1999 and 2019}}, doi = {10.5281/ZENODO.15223343}, year = {2025}, } @article{19839, abstract = {The snow and glaciers of the Peruvian Andes provide vital water supplies in a region facing water scarcity and substantial glacier change. However, there remains a lack of understanding of snow processes and quantification of the contribution of melt to runoff. Here we apply a distributed glacio-hydrological model over the Rio Santa basin to disentangle the role of the cryosphere in the Andean water cycle. Only at the highest elevations (>5000 m a.s.l.) is the snow cover continuous; at lower elevations, the snowpack is thin and ephemeral, with rapid cycles of snowfall and melt. Due to the large catchment area affected by ephemeral snow, its contribution to catchment inputs is substantial (23% and 38% in the wet and dry season, respectively). Ice melt is crucial in the mid-dry season (up to 44% of inputs). Our results improve estimates of water fluxes and call for further process-based modelling across the Andes.}, author = {Fyffe, Catriona Louise and Potter, Emily and Miles, Evan and Shaw, Thomas and Mccarthy, Michael and Orr, Andrew and Loarte, Edwin and Medina, Katy and Fatichi, Simone and Hellström, Rob and Baraer, Michel and Mateo, Emilio and Cochachin, Alejo and Westoby, Matthew and Pellicciotti, Francesca}, issn = {2662-4435}, journal = {Communications Earth and Environment}, publisher = {Springer Nature}, title = {{Thin and ephemeral snow shapes melt and runoff dynamics in the Peruvian Andes}}, doi = {10.1038/s43247-025-02379-x}, volume = {6}, year = {2025}, } @article{19878, abstract = {Rock debris partially covers glaciers worldwide, with varying extents and distributions, and controls sub‐debris melt rates by modifying energy transfer from the atmosphere to the ice. Two key physical properties controlling this energy exchange are thermal conductivity (k) and aerodynamic roughness length (z0). Accurate representation of these properties in energy‐balance models is critical for understanding climate‐glacier interactions and predicting the behavior of debris‐covered glaciers. However, k and z0 have been derived at very few sites from limited local measurements, using different approaches, and most model applications rely on values reported from these few sites and studies. We derive k and z0 using established and modified approaches from data at three locations on Pirámide Glacier in the central Chilean Andes. By comparing methods and evaluating melt simulated with an energy‐balance model, we reveal substantial differences between approaches. These lead to discrepancies between ice melt from energy‐balance simulations and observed data, and highlight the impact of method choice on calculated ice melt. Optimizing k against measured melt appears a viable approach to constrain melt simulations. Determining z0 seems less critical, as it has a smaller impact on total melt. Profile aerodynamic method measurements for estimating z0, despite higher costs, are independent of ice melt calculations. The large, unexpected differences between methods indicate a substantial knowledge gap. The fact that field‐derived k and z0 fail to work well in energy‐balance models, suggests that model values represent bulk properties distinct from theoretical field measurements. Addressing this gap is essential for improving glacier melt predictions.}, author = {Melo Velasco, Juan Vicente and Miles, Evan and McCarthy, Michael and Shaw, Thomas and Fyffe, Catriona Louise and Fontrodona-Bach, Adrià and Pellicciotti, Francesca}, issn = {2169-9011}, journal = {Journal of Geophysical Research: Earth Surface}, number = {6}, publisher = {Wiley}, title = {{Method dependence in thermal conductivity and aerodynamic roughness length estimates on a debris‐covered glacier}}, doi = {10.1029/2025jf008360}, volume = {130}, year = {2025}, } @article{20480, abstract = {Recent studies have argued that air temperatures over many mountain glaciers are decoupled from their surroundings, leading to a local cooling which could slow down melting. Here we use a compilation of on-glacier meteorological observations to assess the extent to which this relationship changes under warming. Statistical modelling of the potential temperature decoupling of the world’s mountain glaciers indicates that currently glacier boundary layers warm ~0.83 °C on average for every degree of ambient temperature rise. Future projections under shared socioeconomic pathway (SSP) climate scenarios SSP 2-4.5 and SSP 5-8.5 indicate that decoupling, and thus relative cooling over glaciers, is maximized during the 2020s and 2030s, before widespread glacier retreat acts to recouple above-glacier air temperatures with its surroundings. This nonlinear feedback will lead to an increased sensitivity to warming from midcentury, with glaciers losing their capacity to affect the local climate and cool themselves.}, author = {Shaw, Thomas and Miles, Evan S. and McCarthy, Michael and Buri, Pascal and Guyennon, Nicolas and Salerno, Franco and Carturan, Luca and Brock, Benjamin and Pellicciotti, Francesca}, issn = {1758-6798}, journal = {Nature Climate Change}, pages = {1212--1218}, publisher = {Springer Nature}, title = {{Mountain glaciers recouple to atmospheric warming over the twenty-first century}}, doi = {10.1038/s41558-025-02449-0}, volume = {15}, year = {2025}, } @article{20546, abstract = {Rocky debris covers around 7.3 % of the global glacier area, influencing ice melt rates and the surface mass balance of glaciers, making the dynamics and hydrology of debris-covered glaciers distinct from those of clean-ice glaciers. Accurate representation of debris in models is challenging, as measurements of the physical properties and thickness of the supraglacial debris layer are scarce. Here, we compile a database of measured and reported bulk physical properties and layer thicknesses of supraglacial debris that we call the supraglacial Debris Database (DebDaB) and that is open to community submissions. The majority of the database (90 %) is compiled from 172 sources in the literature, and the remaining 10 % was previously unpublished. DebDaB contains 8741 data entries for supraglacial debris layer thickness, of which 1770 entries also include sub-debris ablation rates, 179 thermal conductivity of debris, 160 aerodynamic surface roughness length, 79 debris albedo, 59 debris emissivity, and 37 debris porosity. The data are distributed over 84 glaciers in 13 regions in the Global Terrestrial Network for Glaciers. We show regional differences in the distribution of debris thickness measurements in DebDaB and fit simplified Østrem curves to 19 glaciers with sufficient debris thickness and ablation data. The data in DebDaB can be used for energy balance, melt, and surface mass balance studies by incorporating site-specific debris properties or for evaluation of remote sensing estimates of debris thickness and surface roughness. They can also help future field campaigns on debris-covered glaciers by identifying observation gaps. DebDaB's uneven spatial coverage points to sampling biases in community efforts to observe debris-covered glaciers, with some regions (e.g. central Europe and South Asia) well-sampled but others having gaps with prevalent debris (e.g. the Andes and Alaska). Debris thickness measurements are mostly concentrated at lower elevations, leaving higher-elevation debris-covered areas undersampled and suggesting that our knowledge of debris properties might not be representative of all elevations. The aims of DebDaB, as an openly available dataset, are to evolve over time, to be updated, and to add to community submissions as new data on supraglacial properties become available. The data described in this paper can be accessed from Zenodo at https://doi.org/10.5281/zenodo.14224835 (Groeneveld et al., 2025).}, author = {Fontrodona-Bach, Adrià and Groeneveld, Lars and Miles, Evan and McCarthy, Michael and Shaw, Thomas and Melo Velasco, Juan Vicente and Pellicciotti, Francesca}, issn = {1866-3516}, journal = {Earth System Science Data}, number = {8}, pages = {4213--4234}, publisher = {Copernicus Publications}, title = {{DebDaB: A database of supraglacial debris thickness and physical properties}}, doi = {10.5194/essd-17-4213-2025}, volume = {17}, year = {2025}, } @misc{20547, abstract = {DebdaB is a database of measured and reported physical properties and thickness of supraglacial debris that is openly available and open to community submissions. The majority of the database (90%) is compiled from 172 sources in the literature, and the remaining 10% has not been published before. DebDaB contains 8,286 data entries for supraglacial debris thickness, of which 1,852 entries also include sub-debris ablation rates, 167 data entries of thermal conductivity of debris, 157 of aerodynamic surface roughness length, 77 of debris albedo, 56 of debris emissivity and 37 of debris porosity. The data are distributed over 83 glaciers in 13 regions in the Global Terrestrial Network for Glaciers. }, author = {Groeneveld, Lars and Fontrodona-Bach, Adrià and Miles, Evan and McCarthy, Michael and Melo Velasco, Juan Vicente and Shaw, Thomas and Pellicciotti, Francesca and Bauder, Andreas and Buri, Pascal and Kneib, Marin and Kumar, Amit and Mishra, Aditya and Petersen, lene and Renner, Roman and Schmid, Sandro}, publisher = {Zenodo}, title = {{DebDaB: A database of supraglacial debris thickness and physical properties}}, doi = {10.5281/ZENODO.14224835}, year = {2025}, } @article{20669, abstract = {Ice cliffs and supraglacial ponds are key drivers of mass loss on debris-covered glaciers. However, the relationship between melt ponds and adjacent ice cliffs has not been fully explored. We investigated the seasonal drainage patterns of a melt pond on the debris-covered Zhuxi Glacier in southeast Tibet and estimated the mass loss of its adjacent ice cliff during 2023-2024. Using hourly time-lapse photogrammetry we built a series of high-resolution point clouds to quantify the evolution of the ice cliff-pond system. Our findings indicate that subaerial melting and undercutting were the primary mechanisms of ice cliff mass loss during summer. In winter when the pond water level dropped, ice cliff calving became the dominant mode of ice loss. As the water level rose in spring, calving and subaerial melting occurred simultaneously and ice loss from calving accounted for approximately 19.5 % of total ice loss from February to July 2024. Our results reveal the transitional state of this ice cliff-pond system, exhibiting characteristics of both melt hotspots and lake-terminating calving fronts, and highlight the interplay between seasonal drainage-refill pond and differing modes of ice loss on adjacent ice cliff. Future research should focus on additional high-resolution monitoring of similar systems and incorporation of ice cliff-pond dynamics in glacier-scale numerical models. }, author = {He, Zhen and Westoby, Matthew and Ren, Shaoting and Zhao, Chuanxi and He, Yifei and Zhang, Tianzhao and Yang, Wei}, issn = {1727-5652}, journal = {Journal of Glaciology}, publisher = {Cambridge University Press}, title = {{Quantifying the seasonal dynamics of a transitional ice cliff-pond system on a debris-covered glacier}}, doi = {10.1017/jog.2025.10104}, year = {2025}, } @article{20710, abstract = {Mountain glaciers offer opportunities to observe boundary layer exchanges in conditions characterized by predominantly stable stratification, thermally driven winds, and varying surface roughness. Logistical challenges involved in instrumenting glacier surfaces mean that in situ observations remain relatively scarce, limiting the use of this outdoor laboratory. The second Hintereisferner Experiment (HEFEX II) was carried out on an Austrian Alpine glacier during summer 2023. This collaborative endeavor, involving 12 institutions from Austria, France, Germany, Switzerland, and the United Kingdom, represents an unprecedented set of observations of glacier microclimate. Instrumentation on the glacier surface consisted of eight 3-m and two 5-m weather stations equipped with multilevel eddy covariance systems and auxiliary instrumentation, and eight additional lower-specification weather stations. These operated successfully for 26 days with minimal data gaps. During a 3-day intensive observational period, additional instrumentation was deployed: a short-path ultrasonic anemometer installed very close to the glacier surface; a high-speed thermal camera capturing high-resolution boundary layer heat transport at the glacier centerline on a synthetic screen; 3D sampling of the glacier boundary layer using two meteorological UAVs; and a Streamline XR Doppler lidar capturing the structure of the above-valley atmosphere. These novel datasets are valuable for improving understanding of glacier–atmosphere exchange processes, the role of glaciers in valley circulation, and how both might be affected by continued climate change and glacier recession. Here, we detail the scientific goals and implementation of the campaign, describe the general weather conditions, and present first insights into what the observations reveal about the glacier boundary layer features observed during the campaign.}, author = {Nicholson, Lindsey and Stiperski, Ivana and Nitti, Giordano and Prinz, Rainer and Georgi, Alexander and Groos, Alexander R. and Shaw, Thomas and Sauter, Tobias and Haugeneder, Michael and Mott, Rebecca and Sicart, Jean Emmanuel and Brock, Ben W. and Albers, Roland and Allegri, Balthazar and Barral, Hélène and Biron, Romain and Charrondiere, Claudine and Coulaud, Catherine and Fischer, Alexander and Reynolds, Dylan and Richter, Niklas and Schroeder, Marie and Vettori, Phillip and Voordendag, Annelies and Wydra, Carlos}, issn = {1520-0477}, journal = {Bulletin of the American Meteorological Society}, number = {10}, pages = {E2143--E2169}, publisher = {American Meteorological Society}, title = {{The second Hintereisferner experiment (HEFEX II): Initial insights into boundary layer structure and surface–atmosphere exchange processes from intensive observations at a valley glacier}}, doi = {10.1175/BAMS-D-24-0010.1}, volume = {106}, year = {2025}, } @article{20728, abstract = {Glaciers are often located in steep mountain settings and avalanches from surrounding slopes can strongly influence snow accumulation patterns on their surface. This effect has however never been quantified for more than a few glaciers and the impact on the future evolution of glaciers is unclear. We coupled an avalanche and a glacier model to estimate the contribution of avalanches to the accumulation of all glaciers in the world and how this affects their evolution throughout the 21st century. Globally, 3% of the snow accumulation on glaciers comes from avalanches and 1% is removed by avalanches. This net contribution varies between regions and glaciers, with a maximum of 15% for New Zealand. Accounting for avalanches modifies the altitudinal pattern of glacier mass balance and the projected evolution of individual glaciers. The main effects include (1) a longer persistence of small glaciers, with for example three times more ice retained by glaciers smaller than 1 km2 in Central Europe under a low-emission scenario, and (2) an increased sensitivity of high-elevation accumulation zones to future warming. We anticipate the relative influence of avalanches to increase in the future and advocate for a better monitoring of this process and representation in glacier models.}, author = {Kneib, Marin and Maussion, Fabien and Brun, Fanny and Carcanade, Guillem and Farinotti, Daniel and Huss, Matthias and Van Tiel, Marit and Jouberton, Achille and Schmitt, Patrick and Schuster, Lilian and Dehecq, Amaury and Champollion, Nicolas}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Topographically-controlled contribution of avalanches to glacier mass balance in the 21st century}}, doi = {10.1038/s41467-025-65608-z}, volume = {16}, year = {2025}, } @article{18985, abstract = {Persistent multiyear drought (MYD) events pose a growing threat to nature and humans in a changing climate. We identified and inventoried global MYDs by detecting spatiotemporally contiguous climatic anomalies, showing that MYDs have become drier, hotter, and led to increasingly diminished vegetation greenness. The global terrestrial land affected by MYDs has increased at a rate of 49,279 ± 14,771 square kilometers per year from 1980 to 2018. Temperate grasslands have exhibited the greatest declines in vegetation greenness during MYDs, whereas boreal and tropical forests have had comparably minor responses. With MYDs becoming more common, this global quantitative inventory of the occurrence, severity, trend, and impact of MYDs provides an important benchmark for facilitating more effective and collaborative preparedness toward mitigation of and adaptation to such extreme events.}, author = {Chen, Liangzhi and Brun, Philipp and Buri, Pascal and Fatichi, Simone and Gessler, Arthur and Mccarthy, Michael and Pellicciotti, Francesca and Stocker, Benjamin and Karger, Dirk Nikolaus}, issn = {1095-9203}, journal = {Science}, number = {6731}, pages = {278--284}, publisher = {AAAS}, title = {{Global increase in the occurrence and impact of multiyear droughts}}, doi = {10.1126/science.ado4245}, volume = {387}, year = {2025}, } @article{19369, abstract = {Monitoring and estimating mountain snowpack mass over regional scales is still a challenge because of the inadequacy of observational networks in capturing spatiotemporal variability, and limitations in remotely sensed retrievals. Recent work using C-band synthetic aperture radar (SAR) backscatter data from the Sentinel-1 satellite mission has shown good promise for tracking mountain snow depth over specific northern hemisphere ranges, although the broader potential is still unknown. Here, we extend the new Sentinel-1 based modeling framework beyond the northern hemisphere by only utilizing globally available input data, and evaluate different model parametrization and model performance over the Chilean and Argentine Andes mountains, which contain the largest mountain snowpack in the southern hemisphere. The accuracy of Sentinel-1 snow depth estimates is evaluated against an extensive in situ network available for the region. Satellite-retrieved snow depth is found to have poorer performance across the Andes than observed for northern hemisphere mountain ranges because of greater sensitivity to evergreen forest cover and shallower snowpacks. The algorithm does offer some skill but performance is variable and site-dependent. Algorithm performance is best over regions with limited evergreen forest cover (<15%) and snow depths greater than 0.75 m, although the retrievals over-estimate snow depth across most sites. Systemic errors for specific snow classes and across different snow depths are shown, highlighting specific areas in need of further investigation and development.}, author = {Bulovic, N. and Johnson, F. and Lievens, H. and Shaw, Thomas and Mcphee, J. and Gascoin, S. and Demuzere, M. and Mcintyre, N.}, issn = {1944-7973}, journal = {Water Resources Research}, number = {2}, publisher = {Wiley}, title = {{Evaluating the performance of sentinel-1 SAR derived snow depth retrievals over the extratropical Andes cordillera}}, doi = {10.1029/2024WR037766}, volume = {61}, year = {2025}, } @article{21247, abstract = {Seasonal snowmelt in High Mountain Asia is an important source of river discharge. Therefore, observation of the spatiotemporal variations in snow cover at catchment scales using high-resolution satellites is essential for understanding changes in water supply from headwater catchments. In this study, we adapt an algorithm to automatically detect the snowline altitude (SLA) using the Google Earth Engine platform with available high-resolution multispectral satellite archives that can be readily applied for areas of interest. Here, we applied and evaluated the tool to five glacierized watersheds across the Himalayas to quantify the changes in seasonal and annual snow cover over the past 21 years and analyze climate reanalysis data to assess the meteorological factors influencing the SLA. Our findings revealed substantial variations in the SLA among sites in terms of seasonal patterns, decadal trends, and meteorological controls. We identify positive trends in SLA in Hidden Valley (+11.9 m yr−1), Langtang (+14.4 m yr−1), and Rolwaling (+8.2 m yr−1) in the Nepalese Himalayas but a negative trend in Satopanth (−15.6 m yr−1) in the western Indian Himalayas and no significant trend in Parlung in southeastern Tibet. We suggest that the increase in SLA in Nepal was caused by warmer temperatures during the monsoon season, whereas the decrease in SLA in India was driven by increased winter snowfall and reduced monsoon snowmelt. By integrating the outcomes of these analyses, we found that long-term changes in SLA are primarily driven by shifts in the local climate, whereas seasonal variability may be influenced by geographic features in conjunction with climate.}, author = {Sasaki, Orie and Miles, Evan S. and Pellicciotti, Francesca and Sakai, Akiko and Fujita, Koji}, issn = {1994-0424}, journal = {The Cryosphere}, number = {11}, pages = {5283--5298}, publisher = {Copernicus Publications}, title = {{Contrasting patterns of change in snowline altitude across five Himalayan catchments}}, doi = {10.5194/tc-19-5283-2025}, volume = {19}, year = {2025}, } @article{20348, abstract = {Central Asia hosts some of the world’s last relatively healthy mountain glaciers and is heavily dependent on snow and ice melt for downstream water supply, though the causes of this stable glacier state are not known. We combine recent in-situ observations, climate reanalysis and remote sensing data to force a land-surface model to reconstruct glacier changes over the last two decades (1999–2023) and disentangle their causes over a benchmark glacierized catchment in Tajikistan. We show that snowfall and snow depth have been substantially lower since 2018, leading to a decline in glacier health and reduced runoff generation. Remote-sensing observations confirm wider snow depletion across the Northwestern Pamirs, suggesting that a lack of snowfall might be a cause of mass losses regionally. Our results provide an explanation for the recent decline in glacier health in the region, and reinforce the need to better understand the variability of precipitation.}, author = {Jouberton, Achille and Shaw, Thomas and Miles, Evan and Kneib, Marin and Fugger, Stefan and Buri, Pascal and Mccarthy, Michael and Kayumov, Abdulhamid and Navruzshoev, Hofiz and Halimov, Ardamehr and Kabutov, Khusrav and Homidov, Farrukh and Pellicciotti, Francesca}, issn = {2662-4435}, journal = {Communications Earth and Environment}, publisher = {Springer Nature}, title = {{Snowfall decrease in recent years undermines glacier health and meltwater resources in the Northwestern Pamirs}}, doi = {10.1038/s43247-025-02611-8}, volume = {6}, year = {2025}, } @article{20703, abstract = {Glacier melt sustains water discharge from mountain basins during droughts, but ongoing glacier retreat threatens this fundamental capacity. Here, we assess the response of glaciers in the Southern Andes to one of the most severe, persistent, and extensive droughts on record in South America (2010-present), and to projected end-of-century megadroughts. Using glacio-hydrological numerical simulations, we show that despite a mean annual precipitation deficit of 36%, glacier runoff in 2010-2019 remained almost unaltered compared to the preceding decade (2000-2009), sustained by a 10% loss of total ice volume. However, simulations of future glacier evolution indicate that annual and summer glacier runoff could decline by up to 20 ± 11% and 48 ± 6%, respectively, during end-of-century megadroughts compared to pre-2010 levels. Our results project a weakening of the glacier’s buffering role against precipitation deficits during extreme droughts, increasing water scarcity for ecosystems and livelihoods in the mountain regions of South America.}, author = {Ayala, Álvaro and Muñoz-Castro, Eduardo and Farinotti, Daniel and Farías-Barahona, David and Mendoza, Pablo A. and Macdonell, Shelley and Mcphee, James and Vargas, Ximena and Pellicciotti, Francesca}, issn = {2662-4435}, journal = {Communications Earth and Environment}, publisher = {Springer Nature}, title = {{Less water from glaciers during future megadroughts in the Southern Andes}}, doi = {10.1038/s43247-025-02845-6}, volume = {6}, year = {2025}, } @article{18628, abstract = {Arctic tidewater glaciers are retreating, serving as key indicators of global warming. This study aims to assess how subglacial hydrology affects glacier front retreat by comparing two glacier–fjord models of the Hansbreen glacier: one incorporating a detailed subglacial hydrology model and another simplifying the subglacial discharge to a single channel centered in the flow line. We first validate the subglacial hydrology model by comparing its discharge channels with observations of plume activity. Simulations conducted from April to December 2010 revealed that the glacier front position aligns more closely with the observations in the coupled model than in the simplified version. Furthermore, the mass loss due to calving and submarine melting is greater in the coupled model, with the calving mass loss reaching 6 Mt by the end of the simulation compared to 4 Mt in the simplified model. These findings highlight the critical role of subglacial hydrology in predicting glacier dynamics and emphasize the importance of detailed modeling in understanding the responses of Arctic tidewater glaciers to climate change.}, author = {De Andrés, Eva and Muñoz Hermosilla, José M and Shahateet, Kaian and Otero, Jaime}, issn = {2306-5338}, journal = {Hydrology}, number = {11}, publisher = {MDPI}, title = {{The importance of solving Subglaciar hydrology in modeling glacier retreat: A case study of Hansbreen, Svalbard}}, doi = {10.3390/hydrology11110193}, volume = {11}, year = {2024}, }