Meltwater Research Articles

Atmospheric-river-induced foehn events drain glaciers on Novaya Zemlya

Recently, climate extremes have been grabbing attention as important drivers of environmental change. Here, we assemble an observational inventory of energy and mass fluxes to quantify the ice loss from glaciers on the Russian High Arctic archipelago of Novaya Zemlya. Satellite altimetry reveals that 70 ± 19% of the 149 ± 29 Gt mass loss between 2011 and 2022 occurred in just four high-melt years. We find that 71 ± 3% of the melt, including the top melt cases, are driven by extreme energy imports from atmospheric rivers. The majority of ice loss occurs on leeward slopes due to foehn winds. 45 of the 54 high-melt days (>1 Gt d−1) in 1990 to 2022 show a combination of atmospheric rivers and foehn winds. Therefore, the frequency and intensity of atmospheric rivers demand accurate representation for reliable future glacier melt projections for the Russian High Arctic.

Urban territorial planning and integrated watershed management in comparative perspective. the Mendoza (Argentina) and Aconcagua (Chile) rivers

Extreme weather phenomena (heat waves, forest fires, melting glaciers, rising sea levels, warmer and more acidic oceans, hurricanes, droughts and floods, etc.), which are changing and intensifying as a result of climate change, are seriously affecting the lives of people in both urban and rural areas. One of the most urgent problems to be solved is water scarcity.It has been demonstrated that part of this meteorological drought is due to human actions and that the water variable must be integrated into urban and land use planning.The hypothesis of this research is that factors of different nature do not allow achieving territorial planning based on integrated watershed management,in the two investigated case studies: the Mendoza River Basin in Argentina and the Aconcagua River Basin in Chile.The objective of this study was to analyze the regulatory, institutional, governance, sustainability, and climate change components that hinder integrated water resource managementthrough a qualitative methodology. Both case studies reveal obstacles to achieving territorial planning based on integrated watershed management. The Chilean case presents even greater difficulties due to a regulatory and legal framework that still centers on private ownership of water.

Tibetan lake change linked to large-scale atmospheric oscillations via hydroclimatic trajectory

Lakes are known as sentinels of climate change, but their responses may differ from one to another leading to different strategies in lake protection. It is particularly the case in the Tibetan Plateau (TP) of multiple hydrological processes. We employed the Budyko framework to study Tibetan lakes from two lake-basins of contrasting climates for the period between 1980 and 2022: Taro Co Basin (TCB) in a sub-arid climate, and Ranwu Lake Basin (RLB) in a sub-humid climate. Our results showed that total lake area, surface air temperature, evapotranspiration, and potential evapotranspiration increased in both lake-basins, while precipitation and soil moisture increased in the TCB but decreased in the RLB. In the Budyko space, two basins had contrast hydroclimatic trajectories in terms of aridity and evaporative index. The TCB shifted from wetting to drying trend, while the RLB from drying to wetting in early 2000s. Notably, lake change was generally consistent with the drying/wetting phases in the TCB, but in contrast with that in the RLB, which can be attributed to warming-induced glacier melting. Despite of significant correlation with the large-scale atmospheric oscillations, it turned to be more plausible if lake area changes were substituted with basin's hydroclimatic trajectories. Among the large-scale oscillations, El Niño-Southern Oscillation (ENSO) is the most dominant control of lake trends and their drying/wetting shifts. Our findings offer a valuable insight into lake responses to climate change in the TP and other regions.

Examining the glacier-glacial lake interactions of potentially dangerous glacial lakes (PDGLs) under changing climate in Shyok catchment of the Upper Indus Basin

With the ongoing glacier recession, the Himalayan region is witnessing the development of glacial lakes fed by the glacial meltwater. Besides threatening the hydrological regime in the area, the rapid expansion of these lakes at the expense of their feeding glaciers poses a serious risk to the downstream communities in the form of Glacial Lake Outburst Floods, as many of these high-altitude water bodies are vulnerable to this cryospheric disaster under the changing climatic regime. Studying these potentially dangerous glacial lakes (PDGLs) and their feeding glaciers in the context of the changing climate has become crucial in understanding this phenomenon and managing the risk associated with these lakes. The present study focuses on understanding the glacier-lake interactions between the PDGLs and their feeding glaciers under the changing climatic regime. We analyzed the spatio-temporal dynamics of 16 PDGLs, identified in our previous study, and their feeding glaciers for the past three decades (1992–2022), and tried to unravel the relationships between glacier area, glacial lake area, and climatic variables such as temperature and precipitation. The results reveal a rapid expansion of 49.6% in the glacial lake area accompanied by a corresponding glacier recession of 3.27 % and an average terminus retreat of 171 m. The average glacier mass balance was found to be ⁓ −0.22 m w.e. y−1 during this period. The minimum temperature (Tmin) revealed statistically significant increasing trend, whereas the annual precipitation (Pcp) in the area revealed a slightly declining trend in this region. The glacial lake area was found to be in a significant positive correlation with the Tmin and a slight negative correlation with the annual precipitation (Pcp). The glacier area revealed a strong negative correlation with the glacial lake area, Tmax, and the Tmin and a positive correlation with the annual precipitation. The results indicate that the glacial lakes in the region are expanding at the expense of their feeding glaciers under warming climate.

Addressing the Urgent Need for Direct Climate Cooling: Rationale and Options

Abstract Emissions reduction and removal are not proceeding at a pace that will limit global average warming to less than the Paris Agreement targets of 1.5 °C or 2.0 °C. Accelerating global warming is indicated by record high 2023-24 monthly temperatures and annual 2023 global mean surface temperatures around 1.5 °C above pre-industrial levels. Only direct climate cooling has the potential to avert continued temperature rise in the near term and moderate at least some projected climate change disruption including extreme weather, sea level rise, loss of sea ice, glacier and permafrost melting, and coral reef die-off. Strategically deployed at scale, starting in the near term, several cooling measures have the potential to reduce or reverse global warming. Others can exert local or regional cooling influences. The world needs an approach to climate change that extends beyond sole reliance on emission reductions and removal. We propose a) researching, field testing and deploying one or more large-scale cooling influence(s) perhaps initially in polar regions and applying local and regional cooling measures that also support adaptation, b) accelerating emissions reductions with an early prioritization of short-lived climate drivers, and c) deploying large scale carbon removal to draw down legacy greenhouse gas. The authors make no attempt to determine what measures or mix of measures is optimal. That will depend on modeling and experimentation. Only by including properly researched emergency cooling “tourniquets,” in the near-term to our “bleeding” Earth can we slow and then reverse ongoing and increasingly severe climate change in the 21st Century.

Spatial heterogeneity of per- and polyfluoroalkyl substances caused by glacial melting in Tibetan Lake Nam Co due to global warming

Per- and polyfluoroalkyl substances (PFASs) in high-latitude polar regions and the Tibetan Plateau have received widespread international attention. Here, we measured 18 PFASs and 11 major isomers in the lake water, sediment, and surrounding runoff of Lake Nam Co in 2020. The concentrations of ultrashort-chain trifluoroacetic acid (TFA) and perfluoropropanoic acid (PFPrA) and major isomers of perfluoooctanoic acid (PFOA) and perfluoooctane sulfonate acid (PFOS) in water bodies in high-latitude polar regions and the Tibetan Plateau are reported for the first time. The results showed that the concentration of ∑PFASs in glacial runoff was approximately 139 % greater than that in nonglacial runoff. The concentrations of ∑PFASs in the lake water and sediment in the southern lake with multiple glacial runoff events were approximately 113 % and 108 % higher, respectively, than those in the northern lake. The concentrations of short-chain perfluorobutanoic acid (PFBA) and ultrashort-chain TFA and PFPrA, which may be indicators of ice and snow melt, exhibited significant spatial heterogeneity. Overall, the spatial heterogeneity of PFAS concentrations in the water, sediment and surrounding runoff of Lake Nam Co may be caused mainly by glacial melting.

Climate variability and hydrology impacts in east Africa’s Rwenzori Mountains

Study regionThe eastern flank of the 4 km Rwenzori Mountains and the Mobuku catchment 0.25–0.4 N, 29.85–30.1E are the geographic area for detailed analysis. Research focusHydro-climate variability is studied using high resolution satellite- and model- assimilated products in the period 1980–2023. The Mobuku catchment receives rainfall of 3–6 mm/day which generates an eastward discharge of 100 m3/s that declines rapidly downstream, thereby limiting hydro-power availability. New insightsLong-term trends in cloud fraction and potential evaporation reveal a tendency for drying associated with increasing easterly winds, subsidence near the mountain top, and warming of +.04 C/year that is melting glaciers. These constrain runoff on the eastern flank of the Rwenzori Mountains. Low river flows in Dec-Mar correspond with dry air intrusions from the northeast. High river flows in Jul-Nov are modulated by sea temperatures in the Indian Ocean that oscillate east-west at ∼3 year interval. Improved understanding of climate variability will contribute to better management of Uganda’s hydro-power resources.

Analysis of the spatial heterogeneity of glacier melting in Tibet Autonomous Region and its influential factors using the K-means and XGBoost-SHAP algorithms

This study employed machine learning to comprehensively analyze glacier melting in Tibet Autonomous Region (TAR) and its vital influencing factors. Existing machine learning research often lacks detailed explanations, leading to generalized predictions without considering essential driving factors necessary for yielding an insightful understanding of glacier melting dynamics. To overcome these limitations and fulfill multi-level analysis requirements for comprehending glacier melting, this study identifies factors contributing to glacier melting heterogeneity and assesses distinct melting causes in three spatial melted glacier clusters. We utilized K-means unsupervised classification to cluster Tibet melted glaciers into three categories based on temperature, sunshine hours, evapotranspiration, precipitation, normalized vegetation index, and slope. XGBoost algorithm explores the nonlinear relationships of glacier melting with these features and Shapley values were used for model transparency, quantifying feature's influence on the melting process. Investigating geographical heterogeneity among clusters enhanced our understanding of the observed changes. High fitting accuracy (>0.98) enhanced the result reliability, as well. The results show that Tibetan glaciers melt significantly from 2010 to 2020, and the cluster analysis reveals its unique melting characteristics. Melting glaciers in the same cluster are not only similar in characteristics, but also in spatial and geographical distribution, with two of the clusters concentrating in the eastern part of TAR, and the third cluster scattered in the western part of the country. the XGBoost-SHAP analysis efficiently quantifies the contribution of each cluster feature to the glacier melting, revealing the different roles of different clustered features.

An ML‐Based P3‐Like Multimodal Two‐Moment Ice Microphysics in the ICON Model

AbstractMachine learning (ML) is used to build a bulk microphysical parameterization including ice processes. Simulations of the Lagrangian super‐particle model McSnow are used as training data. The ML performs a coarse‐graining of the particle‐resolved microphysics to multi‐category two‐moment bulk equations. Besides mass and number, prognostic particle properties (P3) like melt water, rime mass, and rime volume are predicted by the ML‐based bulk model. The ML‐based scheme is tested with simulations of increasing complexity. As a box model, the ML‐based bulk scheme can reproduce the simulations of McSnow quite accurately. In 3d idealized squall line simulations, the ML‐based P3‐like scheme provides a more realistic extended stratiform region when compared to the standard two‐moment bulk scheme in ICON. In a realistic case study, the ML‐based scheme runs stably, but can not significantly improve the results. This shows that ML can be used to coarse‐grain super‐particle simulations to a bulk scheme of arbitrary complexity.

Constraining future surface air temperature change on the Tibetan Plateau

Abstract The rapid warming of the Tibetan Plateau (TP) in recent decades has led to severe consequences, including the melting of glaciers and snow cover, which further accelerates warming. Accurately projecting the magnitude of future warming is crucial for effective climate change adaptation. However, the projection of future temperature change is model dependent. In this study, we demonstrate a significant correlation between the historical intermodel warming trend and future temperature change, suggesting this relationship could be used to calibrate the best estimate of projections and reduce the uncertainty by observations. For a high emission scenario, the constraint helps to narrow down the uncertainty range of annual and summer temperature change on the western TP by up to 2 °C and 4 °C, respectively, in the end of this century. The most substantial calibrated increase of future change is in winter up to 2 °C, followed by autumn with an increase of up to about 1 °C. Discrepancies of historical warming trend among different observation datasets expose the largest impact on the constrained best estimate compared with emergent relationship derived from different climate models and historical periods.

Crater Morphometry on Callisto

Impact crater formation is affected by the physical properties of planetary crusts, allowing comparison of crater dimensions to serve as a proxy for comparing the crustal properties of different planetary bodies. New topographic profiles of Callisto craters, derived from Galileo-based digital terrain models, are presented, and the crater dimensions recorded. These data were used to derive crater morphometry scaling trends, which were then compared to the established trends of Ganymede and the Moon. Our comparative study suggests that the upper brittle portion of Callisto’s ice crust allows for the retention of steep-sided and elevated rim scarps, while subsurface warmer ice leads to an enhanced uplift and shallowing of the crater bowl. Crater dimensions are similar between Callisto and Ganymede, suggesting that the bulk properties of their near-surface crusts are comparable. The most notable difference between craters on these two Galilean moons were the smaller central pit diameters on Callisto. This difference can be explained if the pit formation on these bodies is controlled by the presence and movement (drainage and/or volatile loss) of impact melt water: the lower impact velocity and/or lower expected crustal heat flow on Callisto will result in less impact melt generation, and thus smaller central pits.

A Review on Global Warming

One of the most important environmental issues of our time is global warming, which is primarily caused by human activity. In order to provide a thorough examination of the phenomenon, this review paper will cover its fundamental causes, observed and anticipated effects on the Earth's climate and ecosystems, as well as proposed mitigating measures. The atmospheric emission of greenhouse gases, particularly carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), is the main cause of global warming. The remarkable rise in greenhouse gas concentrations during the past century has been mostly attributed to the burning of fossil fuels, deforestation, industrial operations, and agricultural activities. The effects of global warming are numerous and extensive. Increasing temperatures have sped up the melting of glaciers and polar ice caps, which has raised sea levels and increased the likelihood of coastal flooding. Extreme weather occurrences, such as heatwaves, droughts, and violent storms, have increased in frequency and have a negative effect on agriculture, water supplies, and vulnerable communities. Additionally, as ecosystems experience extraordinary shifts in temperature and precipitation patterns, biodiversity loss and ecosystem disruption are being seen. This paper presents a variety of potential mitigation tactics that could be used to alleviate the problems caused by global warming. Among these include switching to renewable energy sources, improving energy efficiency, putting reforestation and afforestation programmes into action, and applying sustainable agriculture methods. Additionally, international collaboration and policy frameworks are essential for promoting group initiatives. With significant effects on the environment and society, global warming continues to be a top priority. On a local, national, and international level, cooperation is required to address this complicated issue. This review emphasises how crucial it is to comprehend the underlying causes, effects, and mitigation strategies in order to effectively combat global warming and build a sustainable future for future generations

A hydrogeological conceptual model of aquifers in catchments headed by temperate glaciers

Abstract. For reliable forecasting of the evolution of critical water resources, as well as of potential flood and landslide hazards and their response to climate change, it is necessary to improve the understanding and quantification of unknown aquifer systems in glacierized catchments. We focus on four southeastern outlet glaciers of the main Icelandic ice cap, Vatnajökull. A multidisciplinary approach is carried out, including the acquisition of new in situ data to characterize aquifers and their groundwater dynamics. Moreover, the recharge to aquifers from glacial melt and effective rainfall is estimated. From a detailed analysis of all available data and the determination of the dynamic characteristics of the aquifers, a hydrogeological conceptual model of glacierized catchments is constructed: (i) two distinct aquifers, their hydraulic conductivities and their hydrodynamic responses to climate forcing are identified; (ii) a comprehensive water balance for the whole catchment is obtained; (iii) the subglacial recharge to the aquifers is shown to be 4 times higher than in the proglacial area; and (v) the importance of the impact of the glacial melt recharge on the groundwater system is demonstrated. Thus, we highlight the major role that the groundwater component has in the hydrodynamic functioning of glacierized catchments.

A New Music Composition Technique Using Natural Science Data

The relationship of music and mathematics are well documented since the time of ancient Greece, and this relationship is evidenced in the mathematical or quasi-mathematical nature of compositional approaches by composers such as Xenakis, Schoenberg, Charles Dodge, and composers who employ computer-assisted-composition techniques in their work. This study is an attempt to create a composition with data collected over the course 32 years from melting glaciers in seven areas in Greenland, and at the same time produce a work that is expressive and expands my compositional palette. To begin with, numeric values from data were rounded to four-digits and converted into frequencies in Hz. Moreover, the other data are rounded to two-digit values that determine note durations. Using these transformations, a prototype composition was developed, with data from each of the seven Greenland-glacier areas used to compose individual instrument parts in a septet. The composition <i>Contrast and Conflict</i> is a pilot study based on 20 data sets. Serves as a practical example of the methods the author used to develop and transform data. One of the author’s significant findings is that data analysis, albeit sometimes painful and time-consuming, reduced his overall composing time. The variety and richness of data that exists from all academic areas and disciplines conceivably provide a rich reservoir of material from which to fashion compositions. As more composers explore this avenue of work, different methodologies will develop, and the value of works produced by this method will be evaluated.

Glacier dynamic study of the Terre de Lambert glacier in Greenland based on Landsat 8 and Sentinel-1 data

With global temperatures on the rise, the trend of glacial melting is becoming increasingly evident. This study focuses on the northeastern region of Greenland as the research subject, utilizing remote sensing technology and geographic information technology to study glacial dynamics. Initially, the research processes Landsat 8 data using QGIS to classify the widespread snow and ice cover, facilitating the observation and analysis of its temporal variations. The study then narrows its focus to Terre de Lambert for further analysis. Subsequently, using satellite data from Sentinel-1 and employing SNAP, the research conducts an in-depth analysis of glacier flow speed in specific regions. Through intricate computational models and algorithms, precise glacier flow direction and speed maps are generated. By combining historical data, the study compares and analyzes the glacier flow speed between 2018 and from June 20th to July 14th, 2023. Results indicate that the glacier flow speed in 2023 during the same time frame was faster. Throughout the research process, limitations in current data acquisition and processing methods were identified. Thus, the paper suggests improvements to data acquisition and processing tools to enhance the efficiency of glacier flow speed studies. Theres a fervent hope for the emergence of more convenient, streamlined, and customizable temporal dimension tools for glacier flow speed data in the future. The research findings aim to draw global citizens attention to the issue of glacial melting and inspire collective actions to protect our planet.

Using Iron Stable Isotopes to Quantify the Origins of the Cryoconite Iron Materials in Western China and Exploring Controlling Factors

AbstractIron (Fe) has profound impacts on Earth's ecosystem and global biogeochemical cycles. Fe deposited onto glacier surfaces reduces snow and ice albedo, thereby accelerating glacier melting, and supplying downstream ecosystems with dissolved Fe. However, the origins of atmospheric Fe deposition in glacier regions of western China remain unclear. This study presents novel insights into Fe isotopic composition (refer to δ56Fe) and origins, gained from geochemical analysis of large‐scale cryoconite samples collected from glaciers in western China, which encompass the Tibetan Plateau (TP) and the Tianshan Mountains. Results showed that cryoconite δ56Fe ranged from −1.06 ± 0.07‰ to 0.33 ± 0.04‰, regardless of their concentration. Moreover, anomalous δ56Fe values deviating significantly from the upper continental crust values (with an average of 0.09‰) were detected, indicating a significant impact of anthropogenic Fe materials on the investigated glaciers. This impact was particularly prominent in the margin regions of the TP and its surroundings, but was less apparent in the interior and southern of the plateau. Using MixSIAR isotope mixing model, we determined that coal combustion and other anthropogenic combustion sources (such as liquid fuel combustion and steel smelting) contributed to cryoconite Fe in the range of 6.9%–43.1% and 0.8%–23.4%, respectively. Among these, coal combustion was the predominant anthropogenic source of cryoconite Fe in western China's glaciers. Compared with other sink areas in the Northern Hemisphere, glaciers in western China are obviously affected by anthropogenically sourced Fe. This study has significant implications for understanding glacier‐fed downstream ecosystems and the regional biogeochemical cycle.

Long-term patterns of stream macroinvertebrates in an alpine cirque landscape

Alpine landscapes are notable regarding their sensitivity to environmental change. Surface waters are especially sensitive as many are influenced by glacial meltwaters that are diminishing with the retreat of glaciers worldwide. The Macun Lakes region, Swiss National Park, is an alpine cirque landscape housing a number of lakes interconnected by streams. The area has been non-glaciated for decades, although rock glaciers are still present in the south basin. Surface waters, 10 stream sites in the present study, have been monitored in mid-summer since the year 2001 for physico-chemistry, periphyton and macroinvertebrates (including 74 species of chironomids). Water physico-chemistry revealed that the two main basins in the catchment differed, reflecting the inputs of rock glacier waters in the south basin. However, trends suggest that waters are becoming more similar as rock glacier inputs diminish over time along with a general decrease in nitrogen levels in all waters. Periphyton biomass showed some spatial differences among sites and a general decrease after 2010. Macroinvertebrate assemblages, including chironomids, clearly differed among basins and spatially along the stream network in each basin. Notably, no significant temporal trend was observed in the long-term data for macroinvertebrates, including chironomids, at the monitored sites. The results suggest that lotic macroinvertebrates may be buffered by the interconnectedness of streams and lakes in the landscape, which mitigates major response patterns of running waters to environmental change.

Upward migration of the shallow gas enhances the production behavior from the vertical heterogeneous hydrate-bearing marine sediments

Low gas production rates and insufficient gas yield hinder the large-scale production from natural gas hydrates; a joint production of gas hydrate and its underlying shallow gas is expected to address this limitation. This study focuses on the interaction between heterogeneous hydrate reservoirs and the upward migration of the shallow gas. The results indicated a 38.4 % increase in production efficiency with the assistance of the shallow gas. Specially, the melt water generated from extensive hydrate decomposition could potentially induce a lateral migration of the shallow gas at the interfacial zones of the heterogeneous reservoirs. Further investigation revealed that a lower production pressure would help the release of the shallow gas as well as the hydrate decomposition, thereby contributing to a 64.55 % shorter t90. A faster depressurization rate could facilitate the temperature recovery by intensifying the lateral movement of the shallow gas in the junction layer. Consequently, a proper control of the upward channeling of the shallow gas was suggested in the field test for a successive and secure gas production. Our results could be of help in elucidating the interlayer interference mechanisms and the selection of the depressurization strategy for a better recovery efficiency from the multi-gas source reservoirs.

Modeling glaciation of the Hellas Basin, Mars, for a ‘cold and icy’ late Noachian Paleoclimatic scenario

Global climate models (GCM) predict snow accumulation/glaciation on the Hellas basin eastern rim, where Amazonian glacial landforms are observed. We explore GCM results for Late Noachian-Early Hesperian higher atmospheric pressure/higher obliquity/faint young sun conditions, assess accumulation rates, and use these as input to an ice sheet model. We assess ice sheet growth, thickness, basal temperatures, basal melting water volumes, flow/sliding-ice velocities and the fate of basin floor glacial ice/meltwater. We conclude that significant volumes of glacial ice (with shear-induced basal melting) could have flowed down the basin wall and onto the basin floor, covering the majority with glacial ice. Late Noachian water budgets of up to 1000 m global equivalent layer (GEL) and Hellas floor ice sequestration are implied. Subsequent emplacement of Hesperian volcanic plains superposed on the ice may have caused melting (contact/deferred) and deformation (loading-induced flow/diapirism), potentially accounting for several observed basin floor geologic units.

A glacial lake outburst flood risk assessment for the Phochhu river basin, Bhutan

Abstract. The melting of glaciers has led to an unprecedented increase in the number and size of glacial lakes, particularly in the Himalayan region. A glacial lake outburst flood (GLOF) is a natural hazard in which water from a glacial or glacier-fed lake is swiftly discharged. GLOFs can significantly harm life, infrastructure, and settlements located downstream and can have considerable ecological, economic, and social impacts. Based on a dam breach model, BREACH, and a hydrodynamic model, HEC-RAS (Hydrologic Engineering Centre's River Analysis System), we examined the potential consequences of a GLOF originating from the Thorthomi glacial lake, located within the Phochhu river basin, one of Bhutan's largest and rapidly expanding glacial lakes. Our analysis revealed that following a breach the Thorthomi glacial lake will likely discharge a peak flow of 16 360 m3 s−1 within 4 h. Such a discharge could potentially cause considerable damage, with an estimated 245 ha of agricultural land and over 1277 buildings at risk of inundation. To mitigate ecological, economic, and social impacts on downstream areas, our results emphasise an urgent need for understanding and preparing for the potential consequences of a GLOF from Thorthomi lake. Our findings provide valuable insights for policymakers and stakeholders involved in disaster management and preparedness.