Meltwater Research Articles

Quantifying the impact of snow drought on glacier melting at a Himalayan mountain basin

Tracing emerging contaminants in the Arctic cryosphere: Insights from Spitsbergen (Svalbard Archipelago).

Out in the Cold: The ignored influence of glacial melting on Rhincalanus gigas and R. nasutus (Copepoda, Calanoida) morphology in Antarctic waters.

Understanding the ecology and population dynamics of Arctic appendicularians is increasingly important as oceanographic and climatic conditions continue to change in the high polar systems. Here, the adoption of sediment traps allowed for efficient fixation and preservation of their soft bodies, and validated a representative point sampling for these species regarding their patchy distribution. This study investigates the temporal distribution, phenological rhythms and oceanographic drivers affecting two appendicularian species, Oikopleura (Vexillaria) vanhoeffeni and Fritillaria borealis in Kongsfjorden (Svalbard), a high-Arctic fjord occasionally influenced by Atlantic Water (AW) intrusions and variable sea ice conditions. Based on a time-series of sediment trap samples from 2010 to 2023, O. vanhoeffeni was consistently present and increased in occurrences after 2016. F . borealis , was not detected until 2017, appeared episodically, likely as a non-resident species seasonally introduced into the fjord. Temporal succession of the two species appeared to be influenced by the combination of (i) seasonal variability of thermohaline conditions, (ii) glacial meltwater influencing water mass structure, and (iii) turbidity fluctuations from marine and continental inputs. Oikopleura vanhoeffeni exhibited a well-defined annual cycle with juveniles appearing in autumn (post-reproductive phase), growing through winter-spring, and maturing into reproductive adults by summer. Growth during the polar night was primarily influenced by hydrological conditions, whereas food availability became more important in summer. In contrast, F. borealis showed a peak of adults in spring-summer and juveniles in autumn-winter, indicating a reproductive phase following the spring phytoplankton bloom. These findings contribute to understanding the ecology and population dynamics of Arctic appendicularians under shifting oceanographic and climatic conditions, emphasizing their potential role as sentinel species in a rapidly changing polar environment.

Floods are among Pakistan’s most common and devastating natural disasters, and they are becoming increasingly frequent and intense as a result of climate change, glacial melt, accelerated urbanisation, and weak governance. While coverage of climate change in 2025 has improved compared to 2010 and 2022 in terms of attention to climate change, it still silences local voices and long-term resilience narratives. However, much of the literature on disaster reporting in Pakistan has been descriptive, focusing on one-off events rather than situating them within wider framing theories, agenda-setting, and disaster journalism. This study employs qualitative document analysis (QDA) of a sample (n = 300) of media texts from five mainstream Pakistani media outlets (print and broadcast) published between June and August 2025. Drawing on framing theory and using a hybrid coding framework, this study examines causal attribution, impact reporting, actor representation, and narrative patterns. The results show ongoing sensationalism and political blame frames, low inclusion of community voices, and competing discourses of climate change versus nationalist explanations (especially cross-border water politics). This study contributes to global conversations about disaster communication by demonstrating the role of media in fragile governance settings to reveal and obscure the structural causes of vulnerability. Theoretically, it broadens framing and agenda-setting scholarship by showing the simultaneous functioning of dual causal narratives, scientific (climate-induced) and political (nationalistic). It also provides policy recommendations for more inclusive, accurate, and resilient disaster reporting.

Abstract. Pine Island Bay (PIB), situated in the Amundsen Sea, is renowned for its retreating ice shelves and highly variable sea ice. While brine rejection from sea ice formation and glacial meltwater influence seawater properties, the downstream impacts beneath the region's floating ice shelves remain poorly understood. Here, we exploit an unprecedented multiyear (2020–2023) oceanographic time series from instruments deployed through boreholes beneath the Thwaites Eastern Ice Shelf (TEIS), immediately downstream of PIB, offering new insight into how ice–ocean–atmosphere interactions in PIB shape oceanographic conditions within the subshelf cavity. Our observations reveal a sustained warming and thickening of the modified Circumpolar Deep Water (mCDW) layer near the seabed since January 2020, critical in a region where mCDW drives basal melting beneath West Antarctica's most vulnerable outlet glaciers. Concurrently, the retreat of the multiyear sea ice edge by over 150 km across most of PIB has enhanced the advection of Winter Water, contributing to a cooling of more than 1 °C in the upper 250 m beneath TEIS between July 2021 and January 2023. Superimposed on these trends are episodic temperature and salinity anomalies lasting several weeks, originating in PIB and advecting past the moorings. These events link mobile sea ice cover to subshelf hydrography, as mid-depth waters temporarily warm and increase in salinity, leading to an increase in density, while deeper mCDW simultaneously cools and freshens, reducing its density. Overall, these changes are associated with reduced stratification in the cavity. As sea ice continues to decline in a warming Antarctic climate, our results offer a glimpse into how ocean circulation and basal melting may evolve across the Amundsen Sea Embayment. This dataset provides a critical benchmark for refining process-based models and improving melt rate parameterizations in coupled ice–ocean simulations.

Abstract Flood hazards across High Mountain Asia present pronounced complexity due to the combined influence of rainfall, meltwater, and glacial lake outburst floods (GLOFs). The eastern Himalayan Brahmaputra basin is a critical hotspot of this integrated risk. However, a basin-wide quantification of the individual contributions of these drivers to flood exposure has been lacking. Here, we employ a calibrated coupled hydrological-hydraulic model to provide the first comprehensive assessment. We show that meltwater (snow and glacier melt) contributions to annual maximum floods increase with altitude. At the basin scale, meltwater amplifies population and gross domestic product (GDP) exposure to flooding by 1.3% and 1.5%, respectively. This amplification rises dramatically to 27.9% for population and 33.3% for GDP in high-altitude regions (≥2000 m). Rainfall-derived discharge constitutes the dominant source of flood exposure, followed by meltwater; GLOFs present the least contribution. Nonetheless, GLOFs increase basin-wide population and GDP exposure by 1.2% and 1.3%, and notably intensify to 31.1% and 33.5% above 2000 m. Our findings deliver critical insights for developing targeted flood management strategies in the Brahmaputra basin.

Abstract. Hydrological modeling in large mountainous catchments faces challenges owing to the complex interplay of snowmelt, glacier dynamics, and groundwater contributions, which introduce significant uncertainty in streamflow predictions. This study introduces a Bayesian multi-objective parameter estimation framework to reduce predictive streamflow uncertainty in large mountainous catchments by integrating streamflow likelihood with three auxiliary likelihoods, analyzed individually: snow cover area (SCA), glacier mass balance (GMB), and isotopic composition (I). The well-established generalized likelihood uncertainty estimation (GLUE) method is employed to investigate trade-offs among these likelihoods, providing a detailed assessment of their distinct and combined contributions to hydrological model performance across various flow regimes. The semi-distributed tracer-aided Tsinghua representative elementary watershed-tracer (THREW-T) hydrological model applied in this work captures both rapid surface dynamics and slow-response subsurface processes, offering a comprehensive representation of streamflow variability. Results indicate that isotopic likelihood plays a critical role in reducing low-flow uncertainty by effectively constraining subsurface flow and groundwater–surface water interactions, particularly during winter and early spring when these processes dominate. Conversely, while SCA and GMB likelihoods demonstrate some effectiveness in capturing rapid processes such as snowmelt and glacier melt, their influence is most pronounced during the melting season, with limited effect on reducing overall streamflow uncertainty. This seasonality is reflected in sharpness (SH) values, which measure how much uncertainty is reduced, with isotopic likelihood achieving the highest peak of 0.34 in late winter, whereas SCA and GMB reach maximum SH values of 0.19 and 0.16, respectively, during the melting season. Pareto plots further reveal the synergies and trade-offs associated with each likelihood, underscoring the importance of adopting a multi-objective calibration approach that accounts for seasonal variations in hydrological processes. In addition, the results highlight the critical role of seasonality in shaping the effectiveness of auxiliary likelihoods, emphasizing their potential to improve predictive accuracy and reduce uncertainty in hydrological models.

Climate-driven transformations in the Western Himalaya: projecting glacier retreat, snow cover variability, and future meltwater runoff.

Sediments transported by glacial meltwaters are important sources of trace-metal micronutrients for coastal microbial communities, linking cryospheric processes with ocean fertilization and biogeochemical cycles. Tidewater glacier advance-retreat cycles drive sediment fluxes and influence fjord geochemistry. Here, we used a chemical extraction method to determine the iron and manganese fertilization potential of suspended sediment-plume and iceberg-laden particulate matter from two adjacent, yet geomorphologically distinct, fjords in Southcentral Alaska. We found that the glacier retreat status underpinned the fraction of labile trace-metals within fjord surface plumes, with distinctly lower lability of metals associated with recent and rapid retreat coincident with enhanced erosion and chemical weathering. Particle size did not affect chemical lability, resulting in a well-mixed particle assemblage transported to the coastal ocean. With global tidewater glacier retreat, these results provide implications for future ecosystem fertilization via cryospheric processes and the interpretation of fjord sediment archives.

Hindu Kush Himalaya (HKH) region is often termed the "Third Pole" due to its vast cryospheric reserves. Glaciers are highly sensitive to climate change. Within the Central Karakoram, Shigar Basin represents crucial hydrological system where understanding glacial dynamics is paramount for sustainable water resource management. The impact of climate change on the glaciers of Shigar basin was studied for better sustainable management of water resources and future predictions regarding any risk. A total 448 glaciers were delineated in Shigar Basin and assessed from 1990 to 2022 using Sentinel, Landsat Operational Land Imager (OLI), the Thermal Infrared Sensor (TIRS), and ALOS PALSAR Digital Elevation Model. The total glacier area increased from 2408.3 ± 60 in 1990 to 2425.2 ± 60.2 km2 in 2022 with an increase of about 16.9 km2. Notably, 33% of the glaciated area is covered with supraglacial debris. During the study period, glaciers in the Shigar Basin remained stable, enhancing long-term prospects for water resource planning and risk management in downstream regions reliant on glacial meltwater. For robust future projections, establishment of meteorological stations at higher altitudes and acquisition of field data are imperative for future study of these complex water bodies. These findings are critical for improving climate resilience, regional water security, and informed glacier-related hazard mitigation efforts.

Cruise ship tourists have provided significant revenue for the city of Juneau, Alaska. However, with the surge in visitor numbers and rising temperatures, issues such as overcrowding and glacier melting have emerged. Therefore, the development and implementation of sustainable tourism plans are urgent. In response, this study has developed a sustainable tourism forecasting model for Juneau, using particle swarm optimisation algorithms to simulate changes in various indicators from 2025 to 2046, in order to determine the optimal weight allocation. This study holds important theoretical and practical significance. Theoretically, it enriches the research on sustainable tourism models by incorporating dynamic constraints and long-term environmental changes. Practically, it offers a scientific reference for Juneau to achieve sustainable tourism development. The main innovations of this study include the integration of multi-dimensional factors in the model, the consideration of dynamic constraints and long-term environmental changes, and the exploration of cooperative strategies between tourism revenue distribution and infrastructure investment.

Abstract This article examines the potential of Islamic legal and ethical principles to support environmental protection and climate justice in Pakistan. Given the country’s acute vulnerability to climate change – evidenced by frequent floods, droughts, and glacial melt – there is an urgent need to mobilize culturally grounded legal frameworks that resonate with its social and religious fabric. Islamic law, or Sharīʿah, offers a rich set of values and doctrines such as amānah (trusteeship), maṣlaḥah (public interest), ḥimā (protected zones), and nafh al-ḍarar (prohibition of harm), which emphasize environmental responsibility, intergenerational justice, and balance in creation. This paper argues that integrating these principles into Pakistan’s environmental legal system could strengthen both public legitimacy and policy effectiveness. Drawing upon classical jurisprudence (fiqh), contemporary fatwas, and Islamic environmental ethics, the study explores the compatibility of Sharīʿah-based reasoning with modern climate governance. The paper also analyzes Pakistan’s national climate instruments, such as the Pakistan Climate Change Act 2017, National Climate Change Policy (2021), and environmental regulations under the Pakistan Environmental Protection Act (PEPA), in light of Islamic values. By presenting a model of “Sharīʿah-compatible climate governance,” this study contributes to the wider debate on decolonizing climate law and developing faith-based legal responses to the global ecological crisis.

ABSTRACT An alarming effect of climate change is the accelerated glacier melting, leading to unstable glacial lakes. Rapid thawing may cause sudden lake overflow and discharge due to glacial ice or moraine dam failure. Therefore, monitoring snow coverage, glacier-fed lake surface area, and atmospheric variables is crucial for early glacial lake outburst flood warnings. ”PredSL” is proposed as a novel method for forecasting changes in glacial lake surface area and snow cover using stochastic cellular automata (CA). This study notably advances the field by integrating snow-cover changes with lake surface area expansion, addressing an important limitation of current work. A mathematical model is introduced that accounts for elevation, surface air temperature, and pixel geo-referenced coordinates. The model improves prediction accuracy by modifying thresholds based on Latin Hypercube Sampling (LHS) coefficients. The Mean-Squared-Error (MSE) of the predictions, compared to remote sensing images, ranged from 0.08 to 0.1. This performance surpasses that of existing methods, confirming its efficacy in disaster prediction. Satellite data for model development was gathered every 15-20 days, optimising data availability under clear conditions, facilitating predictions up to 15–20 days ahead. Another key aspect of the proposed method is its strong performance across diverse geographical contexts, demonstrated by its effectiveness in various GLOF incidents at different locations.

Analysis of multibeam sonar and LiDAR data permits interpretation of submarine landforms in eastern Northumberland Strait, part of the St. Lawrence Estuary system, eastern Canada. Landforms are interpreted in the light of multiple forcing mechanisms, principally: (1) glaciation; (2) postglacial relative sea-level fluctuations; (3) spatial variability of tidal currents; and (4) modern sea-ice impact. Bedrock exposures testify to relatively thin glacial sediments. Glacial landforms comprise ribbed moraines and glacial meltwater channels. The study area was emergent in the early Holocene, as evidenced by fluvial channels and former lakes in the Cape Tormentine area. Today, spatially varying tidal forces are strong determinants of geomorphology, and several landforms zones are identified: (1) tidal-swept zones at Abegweit Passage and Caribou, characterized by seafloor scour and scattered bedform fields; (2) the area of weak tidal circulation between the Abegweit and Caribou zones ‒ a low-relief sediment depocenter with littoral zone ridge-and-runnel beach systems, and estuaries; (3) transition zones located between the central depocenter and the tidal-current zones feature sediment drifts; (4) the tidal gyre at East Point, Prince Edward Island, which has formed Milne Bank; and (5) an area east of Caribou, where weaker tidal forces and stronger wave influence are evidenced by alongshore transport embayments between Milne Bank and Souris and the east-facing coast north of Cape Bear, where sediment is trapped in compartments isolated from one another. Modern sea-ice disturbance of the seabed (range -1 to -8 m) is most extensive in the Pictou Banks area.

The Hindu Kush Himalaya (HKH) region faces a growing crisis of air and atmospheric pollution, driven by a complex interplay of factors including rapid urbanization, industrial emissions, agricultural practices, and transboundary pollution. This pollution, encompassing particulate matter, ozone, and other harmful gases, is having devastating consequences across the region. On human health, the polluted air contributes significantly to respiratory illnesses, cardiovascular diseases, and even premature deaths. Vulnerable populations, such as children and the elderly, are particularly susceptible. The region's ecosystems are also under severe stress. Air pollution disrupts plant growth and biodiversity, affecting the delicate ecological balance of the mountains. Deposition of pollutants alters soil chemistry and water quality, impacting forest health and the survival of many species. Water resources, crucial for the livelihoods of millions, are threatened by atmospheric deposition of pollutants. Acid rain and the settling of particulate matter contaminate rivers, lakes, and glaciers, affecting water availability and quality for drinking and irrigation. Agricultural activities are also adversely affected. Air pollution damages crops, reduces yields, and contaminates food sources, impacting food security and farmer livelihoods. Soot deposition accelerates glacier melt, further exacerbating water scarcity and increasing the risk of glacial lake outburst floods. The HKH region's vulnerability to climate change is amplified by air pollution, demanding urgent and coordinated action to mitigate these adverse impacts. Finally, the review emphasizes the need for integrated mitigation strategies and further research to protect the health and livelihoods of the millions of people dependent on the HKH region.

Abstract The isotopic lapse rate plays an important role in paleo-elevation reconstruction. However, there is a lack of a well-defined isotopic lapse rate of river water in the northeastern Tibetan Plateau, limiting the ability of reconstructing the paleo-elevation in the northeastern Tibetan Plateau. To address this knowledge gap, we collected and analyzed stable isotopes of river water in the Bailong River catchment. The δ18O and δD of river water ranged from −13.2 to −8.6 ‰ and −88.0 to −56.7 ‰, respectively. The effect of sub-cloud evaporation on precipitation in low elevation is stronger than that in high elevation based on the meteorological data. Combined with the spatial variations of sub-cloud evaporation effect on precipitation, melting water recharge and evaporation significantly influence the distribution of stable isotopes of river water within the Bailong River catchment. Notably, the δ18O lapse rate of the Bailong River catchment is 1.4 ‰/km, which is much lower than that of other rivers in the eastern Tibetan Plateau. Moreover, the isotopic lapse rate of river water in the eastern Tibetan Plateau gradually decreases with increasing latitude, which is attributed to the contribution of evapotranspiration to precipitation. As an important hydrological process, moisture recycling significantly plays a crucial role in shaping the isotopic compositions of precipitation and thereby affects the isotopic lapse rate. The atmospheric circulation patterns over the Tibetan Plateau are changing due to global warming, which further influences isotopic lapse rates. Therefore, it is urgent to assess the extent to which changes in the source of water vapor driven by global warming have impacted isotopic lapse rate.

Zygnematophycean "glacier algae" form extensive blooms on ablating glacier surfaces despite the ultra-oligotrophic conditions apparent. Previous work has postulated that this oligotrophic bloom paradox is due to i) lower nutrient requirements of glacier algae, ii) efficient uptake and storage of the nutrients available, and/or iii) ineffective characterisation of the actual nutrient environment that glacier algae experience. We investigate the latter here by directly sampling the thin (∼2mm) melt water film in which glacier algal cells reside across three glaciers in Svalbard during the 2023 melt season, comparing to outcomes from more typical bulk ice sampling techniques. Micromelt samples generally contained increased concentrations of ammonium (NH4+), nitrate (NO3-), nitrite (NO2-) and phosphate (PO43-), though trends were not uniform, and concentrations remained well within oligotrophic levels. Several major ion species were significantly increased in micromelt fractions as compared to bulk samples, indicating aeolian deposition and marine aerosol influences on the glacier algal environment. In turn, enhanced micromelt dissolved organic carbon concentrations (DOC) indicated likely DOC delivery by glacier algae to the microbial food web from the onset of bloom formation. Taken together, datasets reveal new fine-scale heterogeneity in the glacier algal meltwater environment.

The Chitral River, a vital tributary of the Indus River originating from the Hindu Kush Himalayan region, is a key source of water for domestic, agricultural, and hydro power needs in Pakistan. Its flow is predominantly governed by snowmelt, glacial runoff, rainfall, and groundwater baseflow, making it highly sensitive to climate change. This study investigates the impact of climate change on future water availability in the Chitral River Basin (CRB) using the Soil and Water Assessment Tool (SWAT) model and Regional Climate Models (RCMs) under RCP4.5 and RCP8.5 emission scenarios. Bias-corrected climate projections indicate significant warming in the basin, with temperature increases ranging from 2.34°C to 5.23°C by the late 21st century. Changes in precipitation are projected to range from 2.42% to 6%, varying across scenarios and timeframes. These shifts in climate variables are expected to alter the hydrological regime, with peak stream flow's anticipated earlier in the year, from June to July. Model simulations suggest an increase in mean annual flow by up to 19.24% under RCP4.5 and 20.13% under RCP8.5 during the mid-century (2041–2070). However, a decline in flows is projected in the late century due to diminishing glacial reserves, highlighting the transient nature of increased runoff driven by glacial melt. This research underscores the critical need for adaptive water resource management strategies to address the impacts of climate change. The findings provide valuable insights for policymakers, water resource managers, and stakeholders, emphasizing the importance of sustainable practices and integrated watershed management to ensure long-term water availability in the Chitral River Basin and downstream regions.

In areas prone to conflict, climate change brings opportunities as well as challenges due to its growing impact on shared natural resources. In order to transform transboundary environmental challenges into opportunities for navigating, fostering peace, and mitigating environmental degradation, this study examines the role of environmental peacebuilding and the potential of ecological connectivity, trans-frontier conservation areas (TFCAs) or peace parks, transboundary protected areas (TBPA), and conservation corridors. These transboundary zones are under growing environmental and geopolitical strain as a result of climate change, which is also accelerating the melting of glaciers, changing ecosystems, and intensifying resource scarcity. This study consists of three case studies: “Cordillera del Cóndor between Peru and Ecuador; the Maloti-Drakensberg Park between Lesotho and South Africa; and the Siachen Glacier within Pakistan and India." This study scrutinizes how environmental peacebuilding might be built upon the connections made between these places through TFCAs, peace parks, and conservation initiatives. The Cordillera del Cóndor has evolved from a conflict zone into a model of peaceful collaboration through shared environmental management. The Maloti-Drakensberg Park demonstrates how peace parks can strengthen and promote sustainable development and biodiversity. The Siachen Glacier, despite its status as one of the world's most militarized zones, offers a unique opportunity for environmental peacebuilding through joint conservation initiatives. This research explores how joint environmental initiatives not only help to mitigate the impacts of climate change but also create pathways for dialogue, trust-building, and long-term peace. By creating TFCAs, or peace parks, and linking conservation corridors across borders, countries can enhance ecological connectivity and biodiversity while building trust, peace, and cooperation. Through the analysis of particular case studies, the study explores that, in spite of its risks, climate change can act as a spur for collaboration. This study illustrations that shared vulnerabilities also provide a unique platform for environmental peacebuilding; establishing environmental conservation corridors, peace parks, and TBPAs not only addresses environmental degradation but also safeguards biodiversity and fosters long-lasting relationships between neighboring nations, transforming contentious landscapes into symbols of ecological and political harmony.