Ice Melt Rates Research Articles

A floating remote observation system (FROS) for full seasonal lake ice evolution studies

A floating remote observation system (FROS) was designed to investigate the full seasonal evolution of lake ice. FROS operates effectively in open water and ice. It can automatically measure meteorological data, such as the air temperature and solar radiation, as well as ice/snow data, including ice thickness and snow depth. These observations help to fill the current knowledge gap of lake ice observations during the early freezing and late melting periods because of the limited bearing capacity of ice cover. A mid-latitude lake was selected for field experiments to verify the effectiveness of FROS, where the duration of the survey was 101 days, of which 97 were during an ice-covered period. The results reveal that the lake ice went through a fast freezing period, equilibrium period, and a melting period, with a maximum ice thickness of 35.5 cm. The ice melting rate was 1.7 cm/day, which was approximately double the ice growth rate of 0.7 cm/day during the fast freezing period. FROS was able to record the complete evolution of lake ice and of different meteorological elements, with good stability in both open water and frozen conditions, and can accommodate wind speeds up to 6.4 m/s. Meanwhile, FROS has good versatility, and other measurement instruments such as chlorophyll and dissolved oxygen sensors, longwave radiometers, and conductivity sensors can be added to it. The application of FROS will be important for calculations of the thermal balance of snow and ice, and studies of the annual and seasonal evolution of ecological characteristics in frozen lakes.

Impacts of short-term wind events on Chukchi hydrography and sea-ice retreat

We seek a better understanding of the summer ice retreat over the Chukchi shelf in the presence of a warm background inflow by investigating mechanisms through which wind forcing mediates changes in sea-ice cover, water-column hydrography, and their inter-related evolution in time. The problem is addressed with observations and an idealized representation of the Chukchi Sea's Central Channel within the Regional Ocean Modeling System (ROMS). An inflow from the south, surface heat fluxes, and wind forcing drives the numerical model. Due to strong atmosphere-ice coupling, direct wind-forced advection of the ice edge emerges as an important factor that controls the oceanic response, including corresponding alterations of the sea surface height. Surprisingly, we find no significant wind control of the cross-frontal eddy transport, due to counterbalancing effects of the frontal density gradient and the pycnocline depth. We propose that wind direction along with differences in the strength of atmosphere-ocean and atmosphere-ice-ocean coupling (drag coefficients) regulate the wind influence on the Chukchi Shelf summer ice retreat and hydrographic structure. Advection of ice away from the inflow reduces the ice melt rate and increases the salinity of the meltwater plume. Advection of ice toward the inflow increases the ice melt rate and decreases the meltwater plume salinity. The identified mechanisms represent steps toward a more complete understanding of the summer conditions in the Chukchi Sea and will help future investigations of seasonally ice-covered shelf ecosystems.

Unevenly distributed CO2 and its impacts on surface energy balance

Atmospheric carbon dioxide (CO2) has affected global surface and atmospheric energy balance since the Industrial Revolution. The spatial distribution of CO2 concentrations derived from satellite observation are introduced into the coupled Beijing Normal University Earth System Model (BNU-ESM) to study the responses of temperature and surface energy balance to non-uniform CO2 distribution under the Representative Concentration Pathway 8.5 scenario to 2100. Global annual mean atmospheric CO2 concentrations are set to equal those specified in the standard uniform CO2 simulations with differences in spatial pattern and seasonal cycles amounting to tens of ppm. Relative to the uniform CO2 simulation, global annual mean surface air temperature increases by 0.44 ± 0.03 °C over 2071–2100 when forced with non-uniformly distributed CO2, in the Arctic by 1.63 ± 0.28 °C and by 0.67 ± 0.08 °C in northern midlatitudes. The non-uniform CO2 simulation increases global surface energy by 0.68 ± 0.06 W m−2, principally due to a 0.73 ± 0.08 W m−2 increase in net downward surface longwave flux. Surface energy balance increases by 0.33 ± 0.11 W m−2 (7.4%) averaged over oceans indicting a significant increase in ocean heat uptake. Surface energy budget averaged over the Arctic summer increases by 0.91 ± 0.68 W m−2 in the non-uniform CO2 simulation, which would have impact on sea ice extent and land ice melt rates with associated feedbacks. The increased surface energy fluxes and temperatures imply reduced time and emission space for greenhouse gases before running into scientific and politically flagged temperature limits.

Mountain Permafrost Hydrology—A Practical Review Following Studies from the Andes

Climate change is expected to reduce water security in arid mountain regions around the world. Vulnerable water supplies in semi-arid zones, such as the Dry Andes, are projected to be further stressed through changes in air temperature, precipitation patterns, sublimation, and evapotranspiration. Together with glacier recession this will negatively impact water availability. While glacier hydrology has been the focus of scientific research for a long time, relatively little is known about the hydrology of mountain permafrost. In contrast to glaciers, where ice is at the surface and directly affected by atmospheric conditions, the behaviour of permafrost and ground ice is more complex, as other factors, such as variable surficial sediments, vegetation cover, or shallow groundwater flow, influence heat transfer and time scales over which changes occur. The effects of permafrost on water flow paths have been studied in lowland areas, with limited research in the mountains. An understanding of how permafrost degradation and associated melt of ground ice (where present) contribute to streamflow in mountain regions is still lacking. Mountain permafrost, particularly rock glaciers, is often conceptualized as a (frozen) water reservoir; however, rates of permafrost ground ice melt and the contribution to water budgets are rarely considered. Additionally, ground ice and permafrost are not directly visible at the surface; hence, uncertainties related to their three-dimensional extent are orders of magnitude higher than those for glaciers. Ground ice volume within permafrost must always be approximated, further complicating estimations of its response to climate change. This review summarizes current understanding of mountain permafrost hydrology, discusses challenges and limitations, and provides suggestions for areas of future research, using the Dry Andes as a basis.

Aerodynamic roughness length of crevassed tidewater glaciers from UAV mapping

Abstract. The aerodynamic roughness length (z0) is an important parameter in the bulk approach for calculating turbulent fluxes and their contribution to ice melt. However, z0 estimates for heavily crevassed tidewater glaciers are rare or only generalised. This study used uncrewed aerial vehicles (UAVs) to map inaccessible tidewater glacier front areas. The high-resolution images were utilised in a structure-from-motion photogrammetry approach to build digital elevation models (DEMs). These DEMs were applied to five models (split across transect and raster methods) to estimate z0 values of the mapped area. The results point out that the range of z0 values across a crevassed glacier is large, by up to 3 orders of magnitude. The division of the mapped area into sub-grids (50 m × 50 m), each producing one z0 value, accounts for the high spatial variability in z0 across the glacier. The z0 estimates from the transect method are in general greater (up to 1 order of magnitude) than the raster method estimates. Furthermore, wind direction (values parallel to the ice flow direction are greater than perpendicular values) and the chosen sub-grid size turned out to have a large impact on the z0 values, again presenting a range of up to 1 order of magnitude each. On average, z0 values between 0.08 and 0.88 m for a down-glacier wind direction were found. The UAV approach proved to be an ideal tool to provide distributed z0 estimates of crevassed glaciers, which can be incorporated by models to improve the prediction of turbulent heat fluxes and ice melt rates.

Numerical simulation of melting of ice accreted on an airfoil

This article presents an innovative concept of de-/anti-icing of the airplane, which is actually a process of utilization of the de-/anti-icing system and of natural melting of ice. We imagine that the airplane with ice accreted on the wings is instantaneously exposed to the airspace with relative high ambient temperature, without considering the process of gradual change in ambient temperature during flight, so as to discuss this concept theoretically and to further explore the natural melting behavior quickly through numerical simulations. The effects of the heat transfer of the wing skin and different Mach numbers on the melting of ice are analyzed with main conclusions that the heat transfer of the wing skin can accelerate the natural melting of ice although the de-/anti-icing system is closed, and that the larger the Mach number the larger the ice melting area and rate and thus the more significant the ice shape changes in the same ice melting time.

Deicing efficiency and snow melting on roof through heat exchange pipe

The energy pile can support the load of upper buildings and exploit the shallow geothermal energy by embedding the traditional ground-source heat pump in the pile foundation of buildings. The steel roof has a large span and poor load-bearing capacity, and it is easy to collapse in the ice and snow weather. Based on the model test and the numerical model, the differences of deicing efficiency on roof through heat exchange pipe under different heat exchange pipe materials, position of pipe layout and pipe spacing on the roof panel, etc. were analyzed in this paper, Results showed that, when the heat exchange pipes were arranged above the panel, the ice melting time was about 2 / 3 of that when heat exchange pipes were arranged under the panel; The shorter the pipe spacing and the denser the pipe arrangement, the faster the ice melting rate.

Investigation of the Thermo-Physical and Mechanical Properties of Coir and Sugarcane Bagasse for Low Temperature Insulation

This research reports on the suitability of Agricultural bi-products as low temperature thermal insulating materials to replace synthetic insulating materials like polyurethane used in food warmers and ice coolers. Coir and sugarcane bagasse chosen for this research was based on literature review and local availability of materials. Coir was obtained from Badagry, Lagos State and Sugarcane bagasse obtained from Batati, Niger State, the materials were washed, sun dried for three days and cut into smaller pieces before being blended into smaller particles using an electric blender. The blended materials (Coir and Bagasse) were sieved into two different sieve size of 0.5 mm and 1.0 mm respectively. The particles sizes were then combined into blend ratios of 50/50, 60/40, and 70/30 using Gum Arabic as binder. Thermal conductivity test showed that 1.0 mm particle size coir mixed with sugarcane bagasse has the lowest thermal conductivity of 0.01467 W/mK whilst that of 0.5 mm particle size has thermal conductivity of 0.01472 W/mK this is lower compared to the measured thermal conductivity of the polyurethane control sample of 0.01832 W/mK. Sample F (1.0 mm particle size,70% coir and 30% bagasse) with a thermal diffusivity of 5.15 m²/s, water absorption capacity of 410 %, UTS of 0.219 MPa, Compressive strength of 0.583 MPa, Specific heat capacity of 1141.3 J/kgK and thermal resistivity of 68.16 W/m/K is most suitable replacement for polyurethane as low temperature thermal insulator. This is corroborated by the performance evaluation test with carried out between polyurethane lined food warmer and bio-composite lined food warmer. The two test samples have close ice melt rate values and the polyurethane slightly edge the Bio-composite insulating material by 1.2 % in efficiency. The edge in efficiency can be accepted as all materials used in the development of the bio-composite insulating material are completely bio-degradable and environmentally friendly.

Recent Changes of Glacial Lakes in the High Mountain Asia and Its Potential Controlling Factors Analysis

The current glacial lake datasets in the High Mountain Asia (HMA) region still need to be improved because their boundary divisions in the land–water transition zone are not precisely delineate, and also some very small glacial lakes have been lost due to their mixed reflectance with backgrounds. In addition, most studies have only focused on the changes in the area of a glacial lake as a whole, but do not involve the actual changes of per pixel on its boundary and the potential controlling factors. In this research, we produced more accurate and complete maps of glacial lake extent in the HMA in 2008, 2012, and 2016 with consistent time intervals using Landsat satellite images and the Google Earth Engine (GEE) cloud computing platform, and further studied the formation, distribution, and dynamics of the glacial lakes. In total, 17,016 and 21,249 glacial lakes were detected in 2008 and 2016, respectively, covering an area of 1420.15 ± 232.76 km2 and 1577.38 ± 288.82 km2; the lakes were mainly located at altitudes between 4400 m and 5600 m. The annual areal expansion rate was approximately 1.38% from 2008 to 2016. To explore the cause of the rapid expansion of individual glacial lakes, we investigated their long-term expansion rates by measuring changes in shoreline positions. The results show that glacial lakes are expanding rapidly in areas close to glaciers and had a high expansion rate of larger than 20 m/yr from 2008 to 2016. Glacial lakes in the Himalayas showed the highest expansion rate of more than 2 m/yr, followed by the Karakoram Mountains (1.61 m/yr) and the Tianshan Mountains (1.52 m/yr). The accelerating rate of glacier ice and snow melting caused by global warming is the primary contributor to glacial lake growth. These results may provide information that will help in the understanding of detailed lake dynamics and the mechanism, and also facilitate the scientific recognition of the potential hazards associated with glacial lakes in this region.

Microwave Induction Heating of Polymer-Modified Asphalt Materials for Self-Healing and Deicing

This study evaluates the influence of polymer-modification on the induction heating capability of asphalt mastic in a microwave field, and investigates how effectively this approach can be utilized for ice melting and self-healing purposes. To this end, different asphalt mastic mixtures with different polymer-modification and mixing procedures were tested under microwave field exposure for induction heating capability, ice-melting ability, and self-healing capacity. The mixtures were made through warm-mix and hot-mix procedures with four bituminous binders, including virgin (unmodified) asphalt and the same binder modified with three types of polymers. The results showed the effectiveness of microwave induction heating of asphalt mastic for both crack-healing and deicing purposes. The binder type was found to influence the ice melting and crack healing rates, such that using a warm-mix asphalt binder resulted in a more efficient heat generation and conduction than using a virgin asphalt binder. While polymer-modification undermined induction-heating, ice-melting, and self-healing performances, SBS-modified asphalt binders exhibited better performance than the other polymer-modified binders.

A Multiperiod Model for Assessing the Socioeconomic Impacts of Oil Spills during Arctic Shipping.

As the rate of ice melt in the Arctic increases, the potential for shipping activities is also increasing.However, infrastructure along the northwest passage (NWP) in Canada's Arctic is almost nonexistent. This presents major challenges to any response efforts in the case of a natural disaster. Also, the Arctic is home to many indigenous communities, as well as flora and fauna. Thus, it is of vital importance to protect the livelihood of the rights holders in this area and the Arctic marine environment. To do this, it is necessary to develop a decision-making tool to assess the potential risk of pollutants arising from increased shipping activity. Understanding such, this article assesses the impacts of a potential oil spill on communities in the Canadian Arctic. The consequences of risk are presented using a multiperiod model while the likelihood is analyzed using Bayesian Network. The output of the multiperiod model is incorporated into an influence diagram for risk assessment purposes. The Bayesian model benefits from expert elicitation from the crew aboard a research ship passing through the NWP. Information was also obtained from marine insurance companies, government representatives, and other Arctic specialized professionals. The risk-based model is subsequently applied to the Canadian Arctic area, with the aim of evaluating the impact of a potential oil spill through shipping.

Role of Intense Arctic Storm in Accelerating Summer Sea Ice Melt: An In Situ Observational Study

AbstractIntense storms have been more frequently observed in the Arctic during recent years, in coincidence with extreme sea ice loss events. However, it is still not fully understood how storms drive such events due to deficient observations and modeling discrepancies. Here we address this problem by analyzing in situ observations acquired during an Arctic expedition, which uniquely captured an intense storm in summer 2016. The result shows a pronounced acceleration of sea ice loss during the storm process. Diagnostic analysis indicates a net energy loss at the ice surface, not supporting the accelerated melting. Although the open water surface gained net heat energy, it was insufficient to increase the mixed‐layer temperature to the observed values. Dynamic analysis suggests that storm‐driven increase in ocean mixing and upward Ekman pumping of the Pacific‐origin warm water tremendously increased oceanic heat flux. The thermal advection by the Ekman pumping led to a warmed mixed layer by 0.05°C–0.12°C and, in consequence, an increased basal sea ice melt rate by 0.1–1.7 cm day−1.

Numerical Investigation on the Evolution of Thin Liquid Layer and Dynamic Behavior of an Electro-Thermal Drilling Probe during Close-Contact Heat Transfer

This study investigates the transient behavior of an electro-thermal drilling probe (ETDP) during a close-contact melting process within a glacier. In particular, the present work analyzes the effect of the tip temperature on the formation of molten thin liquid films and the subsequent rate of penetration (ROP) through numerical simulation. We used the commercial code of ANSYS Fluent (v.17.2) to solve the Reynolds-averaged Navier–Stokes equation, together with an energy equation considering the solidification and melting model. The ROP of the drilling probe is determined based on the energy balance between the heating power and melting rate of ice. As the results, the ETDP penetrates the ice through a close-contact melting process. The molten liquid layer with less than 1 mm of thickness forms near the heated probe tip. In addition, the ROP increases with the heated temperature of the probe tip.

Spatial–temporal variation of land use and land cover change in the glacial affected area of the Tianshan Mountains

During the past decades, land use/land cover change (LUCC) has occurred in the glacial affected areas at unpredictable rates driven by natural and human factors. Monitoring and identifying the spatial and temporal land cover changes and driving forces in this unique type of region provides a scientific basis for understanding the changing process of the Earth's surface, helping to reveal the impact of climate change and human activities on LUCC. In this study, the Tianshan Mountains (TSMs), which are located in the hinterland of Eurasia, were selected to investigate the LUCC of its typical glacial affected areas that have significant regional particularities. LUCC processes in the TSMs in China over the past 35 years were analyzed using a dynamic change model, a landscape pattern index, a centroid transfer model, and geoinformation Tupu based on the land use data of 1980, 1990, 2000, and 2015. The results show that the areas of cultivated and built-up lands immensely increased by 45.87% and 187.10%, respectively. Correspondingly, the areas of bare land and ice and snow cover decreased by 26.76% and 37.93%, respectively. The land use change in the TSMs was characterized by different stages, and high conversion rates and intensities were obtained from 2000 to 2015. The landscape change was mainly reflected in the significant increase in the number of patches and the simplification and regularization of patch shapes. The spatial connectivity of different land use types also increased. The temperature and precipitation in the region showed increasing trends, and the melting rate of ice and snow cover significantly accelerated. This study can help achieve a dynamic LUCC model to investigate the interacting influences of climate change and human activities in glacial affected areas.

Risk of tipping the overturning circulation due to increasing rates of ice melt

Risk of tipping the overturning circulation due to increasing rates of ice melt

Material design and performance analysis of the anti-ice and antiskid wear layer on pavement

A design method for an anti-ice and antiskid wear layer on pavement is presented in this paper. A kind of bonding material with excellent properties has been developed that can maintain a good bonding ability in high and low temperature environments and has good UV aging resistance. Porous high-strength shale aggregates are used to replace portions of stone, and the functional characteristics of the ice inhibition of the wear layer are realized by soaking in saturated salt water. The results show that after adding ceramsite, the freezing point of pavement can be reduced by approximately 5 °C at most and the ice melting rate can be increased by approximately 30%. After continuous soaking for ten days, salt can still be precipitated from the aggregate, which can inhibit the formation of an ice film to a certain extent. As the proportion of ceramsite increases, the polishing resistance of the pavement increases. Under conditions of flooding and freezing, the BPN of the aggregate mixed with ceramsite is approximately 50% higher than that of andesite aggregate. The wear layer can provide a good anti-ice and antiskid performance, which is helpful for traffic safety under wintry conditions.

Risk of tipping the overturning circulation due to increasing rates of ice melt

Central elements of the climate system are at risk for crossing critical thresholds (so-called tipping points) due to future greenhouse gas emissions, leading to an abrupt transition to a qualitatively different climate with potentially catastrophic consequences. Tipping points are often associated with bifurcations, where a previously stable system state loses stability when a system parameter is increased above a well-defined critical value. However, in some cases such transitions can occur even before a parameter threshold is crossed, given that the parameter change is fast enough. It is not known whether this is the case in high-dimensional, complex systems like a state-of-the-art climate model or the real climate system. Using a global ocean model subject to freshwater forcing, we show that a collapse of the Atlantic Meridional Overturning Circulation can indeed be induced even by small-amplitude changes in the forcing, if the rate of change is fast enough. Identifying the location of critical thresholds in climate subsystems by slowly changing system parameters has been a core focus in assessing risks of abrupt climate change. This study suggests that such thresholds might not be relevant in practice, if parameter changes are not slow. Furthermore, we show that due to the chaotic dynamics of complex systems there is no well-defined critical rate of parameter change, which severely limits the predictability of the qualitative long-term behavior. The results show that the safe operating space of elements of the Earth system with respect to future emissions might be smaller than previously thought.

Antarctic Water Masses and Ice Shelves: Visualizing the Physics.

High-resolution simulation of global climate physics enables us to model how the climate may change under a variety of future scenarios. Such simulations produce vast amounts of information and dense datasets. If interrogated in tandem, these datasets can provide holistic, vital information on Earth's many integrated systems by revealing the manifold interrelated properties of the atmosphere, ocean, and polar ice, framed by real-world terrain in three-dimensional space as they vary over time. To accomplish this, climate scientists have joined with computer scientists and an artist to develop techniques enabling scientists to see these relationships. The impact of ocean water properties on Antarctic ice shelves illustrates the benefit of this analysis in understanding land ice melt rates and thus sea-level rise.

GHub: Building a glaciology gateway to unify a community

AbstractThere is no consensus on how quickly the earth's ice sheets are melting due to global warming, nor on the ramifications to sea level rise. Due to its potential effects on coastal populations and global economies, sea level rise is a grave concern, making ice melt rates an important area of study. The ice‐sheet science community consists of two groups that perform related but distinct kinds of research: a data community, and a model building community. The data community characterizes past and current states of the ice sheets by assembling data from field and satellite observations. The modeling community forecasts the rate of ice‐sheet decline with computational models validated against observations. Although observational data and models depend on one another, these two groups are not well integrated. Better coordination between data collection efforts and modeling efforts is imperative if we are to improve our understanding of ice sheet loss rates. We present a new science gateway, GHub, a collaboration space for ice sheet scientists. This web‐accessible gateway will host datasets and modeling workflows, and provide access to codes that enable tool building by the ice sheet science community. Using GHub, we will collect and centralize existing datasets, creating data products that more completely catalog the ice sheets of Greenland and Antarctica. We will build workflows for model validation and uncertainty quantification, extending existing ice sheet models. Finally, we will host existing community codes, enabling scientists to build new tools utilizing them. With this new cyberinfrastructure, ice sheet scientists will gain integrated tools to quantify the rate and extent of sea level rise, benefitting human societies around the globe.

Detecting short-term surface melt over Vestre Broggerbreen, Arctic glacier using indigenously developed unmanned air vehicles

In the Arctic, the impacts of global warming are strong and the rate of ice melting is increasingly accelerating due to warmer temperatures relative to snow accumulation. With recent advances in unmanned air vehicle (UAV) technology and image processing techniques, field measurements for cryosphere studies have gained significance today. In the current report, an attempt is being made to measure glacier surface melt over a four-day period using UAV acquisitions and field measurements to improve India's scientific credentials in polar science. Two aerial surveys were performed on 14 and 17 September 2019 using an indigenous Quadcopter UAV over a portion of the Ablation area of Vestre Broggerbreen glacier, Svalbard, Arctic. To measure precise surface melt, surface topography reconstructed from the acquired aerial images is processed. Results concluded that a surface melt was observed ranging from 0.013 to 0.065 m, which agreed with the measurements in situ.