Liquid Water Research Articles

Contemporary movement of rock glaciers in the La Sal and Uinta Mountains, Utah, USA

Rock glaciers are common landforms in mountainous areas of the western US. The motion of active rock glaciers is a key indicator of ice content, offering connections to climate and hydrologic systems. Here, we quantified the movement of six rock glaciers in the La Sal and Uinta Mountains of Utah through repeat differential GPS surveying. Networks of 10–41 points on each rock glacier were surveyed in September, 2021; July, 2022; September, 2022; and July, 2023. We found that all features are moving with average annual rates of motion from 1.5 ± 0.8 to 18.5 ± 7.5 cm/yr. Rock glaciers move up to 3x faster in the summer than in the winter, and rates of motion were greater in 2023 after a winter with above-average snowfall, emphasizing the role of liquid water availability. Velocities of individual points in the winter of 2021–22 are positively correlated with velocities during the winter of 2022–23, suggesting that spatial variability of motion is not stochastic, but rather reflects internal properties of each rock glacier. Bottom temperature of snow measurements during winter, and the temperature of springs discharging water in summer, suggest that these rock glaciers contain modern permafrost. Radiocarbon data document advance of one rock glacier during the Little Ice Age. Our GPS dataset reveals complicated patterns of rock glacier movement, and the network of survey points we established will be a valuable baseline for detecting future cryosphere change in these mountains.

Effects of liquid water injection on flame surface topology and propagation characteristics in spray flames: A direct numerical simulation analysis

The effects of water injection on flame surface topology and local flame propagation characteristics have been analyzed for statistically planar turbulent n-heptane spray flames with an overall (i.e., liquid + gaseous) equivalence ratio of unity using carrier-phase direct numerical simulations. Most fuel droplets have been found to evaporate as they approach the flame even though some droplets can survive until the burnt gas side is reached, whereas water droplets do not significantly evaporate ahead of the flame and the evaporation of water droplets starts to take place in the reaction zone and is completed within the burnt gas. However, the gaseous-phase combustion occurs predominantly in fuel–lean mode although the overall equivalence ratio remains equal to unity. The water injection has been found to suppress the fuel droplet-induced flame wrinkling of the progress variable isosurface under the laminar condition, and this effect is particularly strong for small water droplets. However, turbulence-induced flame wrinkling masks these effects, and thus, water injection does not have any significant impact on flame wrinkling for the turbulent cases considered here. The higher rate of evaporation and the associated high latent heat extraction for smaller water droplets induce stronger cooling effects, which weakens the effects of chemical reaction. This is reflected in the decrease in the mean values of density-weighted displacement speed with decreasing water droplet diameter. The weakening of flame wrinkling as a result of injection of small water droplets is explained through the curvature dependence of the density-weighted displacement speed. The combined influence of cooling induced by the latent heat extraction of water droplets and flame surface flattening leads to a decrease in volume-integrated burning rate with decreasing water droplet diameter in the laminar cases, whereas the cooling effects are primarily responsible for the drop in burning rate with decreasing water droplet diameter in the turbulent cases.

Solidified water at room temperature hosting tailored fluidic channels by using highly anisotropic cellulose nanofibrils

Highly anisotropic cellulose nanofibrils can solidify liquid water, creating self-supporting structures by incorporating a tiny number of fibrils. These fibrillar hydrogels can contain as much as 99.99 wt% water. The structure and mechanical properties of fibrillar networks have so far not been completely understood, nor how they solidify the bulk water at such low particle concentrations. In this work, the mechanical properties of cellulose fibrillar hydrogels in the dilute regime from a wt% perspective have been studied, and an elastoplastic model describing the network structure and its mechanics is presented. A significant insight from this work is that the ability of the fibrils to solidify water is very dependent on particle stiffness and the number of contact points it can form in the network structure. The comparison between the experimental results and the theoretical model shows that the fibrillar networks in the dilute regime form via a non-stochastic process since the fibrils have the time and freedom to find contact points during network formation by translational and rotational diffusion. The formed, dilute fibrillar network deforms by sliding fibril contacts upon straining the network beyond its elastic limit. Our results also show that before macroscopic failure, the fibril contacts are restored once the load is released. The exceptional properties of this solidified water are exploited to host fluidic channels, allowing directed fluid transportation in water. Finally, the microfluidic channels formed in the hydrogels are tailored by the layer-by-layer technique to be interactive against external stimuli, a characteristic envisioned to be useful in biomedical applications.

The preliminary measurements of water cloud microphysical properties using multiple scattering Raman lidar

Clouds play an important role in the energy balance and water cycle for the Earth-Atmosphere system, and the accurate measurement of their macro-and microphysical properties is important for understanding atmospheric physical processes, studying aerosol-cloud interactions and improving numerical model parameterization schemes. In this paper, a multiple scattering Raman lidar system is developed, which greatly simplifies the structure of the optical system and solves the complexity of the optical system in detecting the cloud characteristic parameters by adopting the dual field-of-view (FOV) technique. Based on the Quasi-Small-Angle (QSA) approximation model, the forward single or multiple scattering signals of cloud droplet particles at the bottom of the cloud layer at the dual-FOV channel and the vibrational Raman backscattering signals of nitrogen molecules are simultaneously detected. Using the correlation between the width of the forward scattering peak and the particle size of the cloud droplets, an iterative algorithm for the Raman signal is proposed for retrieving cloud parameters such as the extinction coefficient, the effective radius, and the liquid water content (LWC). To verify the feasibility of the system and retrieval algorithms, some preliminary measurements were carried out and the resulting liquid water content was compared and verified by combined observations with a co-located microwave radiometer. The experimental results show that the average deviation of the liquid water content is 0.004 g/m3, and the relative error is 20%. The system has an ability to invert cloud microphysical properties, which provides an effective method for further study of aerosol-cloud interactions.

A parametric study on the effect of liquid water content and droplet median volume diameter on the ice distribution and anti-icing heat estimation of a wind turbine airfoil

A parametric study on the effect of liquid water content and droplet median volume diameter on the ice distribution and anti-icing heat estimation of a wind turbine airfoil

Size-resolved water-soluble organic carbon and its significant contribution to aerosol liquid water

Size-segregated aerosols collected in Beijing from 2021 to 2022 were used to investigate the contribution of organic aerosols to the aerosol liquid water content (ALWC), the influencing factors of ALWC, and the concentrations and size distribution characteristics of water-soluble organic carbon (WSOC) after clean air actions. The results showed that the concentration of WSOC in particulate matter (PM)1.8 was 3.52 ± 2.43 μg/m3 during the sampling period. Obvious changes were observed in the size distribution of WSOC after clean air actions, which may be attributed to the enhancement of atmospheric oxidation capacity and the decrease in PM concentration. The contribution of organic aerosols to the ALWC in fine PM was 18.1 % during the sampling period, which was more significant at lower particles concentration and smaller particle size ranges. The ambient relative humidity (RH) and the ratio of NO3−/SO42− had an apparent influence on ALWC. The continuous increase in the nitrate proportion significantly reduced the deliquescence point of the aerosols, making them prone to hygroscopic growth at lower RH. Analysis of the relation among nitrogen oxidation ratio (sulfur oxidation ratio), ALWC and PM1.8 mass concentrations suggests that organic matter has a significant effect on the formation of secondary inorganic aerosols in the initial phase of pollution formation and plays a crucial role in aerosol pollution formation in Beijing. These results are conducive to understanding the formation mechanism of aerosols and provide scientific data and theoretical support for the formulation of more effective emission-reduction measures.

Surface Air‐Pressure Measurements From Space Using Differential Absorption Radar on the Right Wing of the 60 GHz Oxygen Band

AbstractSurface air pressure is one of the most important parameters used in Numerical Weather Prediction (NWP) models. Although it has been measured using weather stations on the ground for many decades, the numbers of measurements are sparse and concentrated on land. Few measurements from buoys and ships are available over ocean. Global measurements can only be achieved by using remote sensing from Space, which is challenging; however, a novel design using Differential Absorption Radar (DAR) can provide a potential solution. The technique relies on two facts: first the electromagnetic fields are absorbed mainly by oxygen and water vapor, and second that oxygen is well mixed. In this work we discuss a space‐borne concept, which aims at providing, over the ocean, consistent, and regular observations for determining surface air pressure from space by a design of a multi‐tone radar operating on the upper wing of the O2 absorption band with tones from 64 to 70 GHz. Simulations of radar vertical profiles based on the output of a state of‐the‐art microphysical retrievals applied to the A‐Train suite of sensors are exploited to establish the performance of such a system for surface pressure determination. In particular the identification and quantification of errors introduced by the presence of water vapor, cloud liquid water and rain water and the potential of a correction via the three‐tone method is discussed. Errors introduced by surface measurement noise and temperature profile uncertainties are discussed as well. Results show that accuracy between 2 and 5 hPa is at reach.

Hydration and wetting mechanism of borosilicate – Polyvinyl alcohol (PVA) hybrid aerogels of potential bioactivity

Mesoporous borosilicate – polyvinyl alcohol (PVA) hybrid aerogels show positive bioactivity when interacting with dental pulp stem cells. The surface characteristics and the nanostructures of the hydrated aerogel particles are important in determining the biological response. This study reports the comparative structural characterization of pristine and stepwise hydrated hybrid aerogels, and proposes a qualitative mechanism for the wetting and pore-filling processes of these mesoporous materials. Nuclear magnetic resonance (NMR) relaxometry and cryoporometry revealed the extensive hydration of PVA macromolecules in the hybrid skeleton when contrasted to the wetting of pure silica aerogels. In spite of this extensive hydration, the open and permeable pore-structure of the hybrid borosilicate-PVA aerogels are preserved even when completely filled with liquid water. The conservation of the nanoscale architecture of the hybrid aerogels upon wetting was further confirmed by SANS. Finally, it was shown that the incorporation of microcrystalline hydroxyapatite into the hybrid skeleton does not alter the advantageous morphological features and wetting mechanism of the hybrid aerogels. The rough nanostructured skeleton is advantageous for cell binding and ensures facile mass transport through the particles in aqueous suspensions.

Seasonal Variation in Vertical Structure for Stratiform Rain at Mêdog Site in Southeastern Tibetan Plateau

Mêdog is located at the entrance of the water vapor channel of the Yarlung Tsangpo Great Canyon on the southeastern Tibetan Plateau (TP). In this study, the seasonal variation in the microphysical vertical structure of stratiform precipitation at the Mêdog site in 2022 was investigated using micro rain radar (MRR) observations, as there is a lack of similar studies in this region. The average melting layer height is the lowest in February, after which it gradually increases, reaches its peak in August, and then gradually decreases. For lower rain categories, the vertical distribution of small drops remains uniform in winter below the melting layer. The medium-sized drops show slight increases, leading to negative gradients in the microphysical profiles. Slight or evident decreases in concentrations of small drops are observed with decreasing height in the premonsoon, monsoon, and postmonsoon seasons, likely due to significant evaporation. The radar reflectivity, rain rate, and liquid water content profiles decrease with decreasing height according to the decrease in concentrations of small drops. With increasing rain rate, the drop size distribution (DSD) displays significant variations in winter, and the fall velocity decreases rapidly with decreasing height. In the premonsoon, monsoon, and postmonsoon seasons, the concentrations of large drops significantly decrease below the melting layer because of the breakup mechanism, leading to the decreases in the fall velocity profiles with decreasing height during these seasons. Raindrops with sizes ranging from 0.3–0.5 mm are predominant in terms of the total drop number concentration in all seasons. Precipitation in winter and postmonsoon seasons is mainly characterized by small raindrops, while that in premonsoon and monsoon seasons mainly comprises medium-sized raindrops. Understanding the seasonal variation in the vertical structure of precipitation in Mêdog will improve the radar quantitative estimation and the use of microphysical parameterization schemes in numerical weather forecast models over the TP.

Modification and Validation of the Soil–Snow Module in the INM RAS Climate Model

This paper describes the modification of a simple land snow cover module of the INM RAS climate model. The possible liquid water and refreezing of meltwater in the snow layer are taken into account by the proposed parameterization. This is particularly important for modelling the transition season, as this phenomenon is mainly observed during the formation and melting of the snow cover when the surface temperature fluctuates around 0 °C. The snow density evolution simulation is also added. This parameterization is implemented in the INM-CM snow module and verified on observation data using the ESM-SnowMIP-like protocol. As a result, the INM-CM mean climate snow melt periods are refined, particularly in middle and high latitudes. The snow-covered area according to the model is also improved. In the future, a modified version of the land snow module can be used, coupled with a snow albedo model that takes into account snow metamorphism. This module can also be applied to sea ice snow.

Land surface modeling informed by earth observation data: toward understanding blue–green–white water fluxes in High Mountain Asia

ABSTRACT Mountains are important suppliers of freshwater to downstream areas, affecting large populations in particular in High Mountain Asia (HMA). Yet, the propagation of water from HMA headwaters to downstream areas is not fully understood, as interactions in the mountain water cycle between the cryo-, hydro- and biosphere remain elusive. We review the definition of blue and green water fluxes as liquid water that contributes to runoff at the outlet of the selected domain (blue) and water lost to the atmosphere through vapor fluxes, that is evaporation from water, ground, and interception plus transpiration (green) and propose to add the term white water to account for the (often neglected) evaporation and sublimation from snow and ice. We provide an assessment of models that can simulate the cryo-hydro-biosphere continuum and the interactions between spheres in high mountain catchments, going beyond disciplinary separations. Land surface models are uniquely able to account for such complexity, since they solve the coupled fluxes of water, energy, and carbon between the land surface and atmosphere. Due to the mechanistic nature of such models, specific variables can be compared systematically to independent remote sensing observations – providing vital insights into model accuracy and enabling the understanding of the complex watersheds of HMA. We discuss recent developments in spaceborne earth observation products that have the potential to support catchment modeling in high mountain regions. We then present a pilot study application of the mechanistic land surface model Tethys & Chloris to a glacierized watershed in the Nepalese Himalayas and discuss the use of high-resolution earth observation data to constrain the meteorological forcing uncertainty and validate model results. We use these insights to highlight the remaining challenges and future opportunities that remote sensing data presents for land surface modeling in HMA.

Liquid Hot Water (LHW) and Hydrothermal Carbonization (HTC) of Coffee Berry Waste: Kinetics, Catalysis, and Optimization for the Synthesis of Platform Chemicals

Colombia is the world’s leading producer of mildly washed arabica coffee and produces 12.6 million bags of green coffee, but at the same time, 784,000 tons of waste biomass are dumped in open fields, of which only 5% is recovered or used. The objective of this project was to evaluate the production of platform chemicals from these coffee wastes for sustainable resource management. To achieve this, biomass characterization was carried out using proximate analysis, ultimate analysis, and structural analysis. Hydrothermal valorization was carried out at a temperature range of 120–180 °C (LHW) and 180–260 °C (HTC) for one hour. The platform chemicals obtained were quantified by HPLC-RI and monitored by pH and conductivity, and the solid fraction was characterized by monitoring the functional groups in IR spectroscopy and elemental analysis. Hydrolysis processes were obtained at 150 °C, production of platform chemicals at 180 °C, and maximum concentration at 180 °C-4 h; over 200 °C, degradation of the products in the liquid fraction starts to take place. Homogeneous basic and acid catalysts were used to improve the yields of the reaction. The kinetics of the hydrolysis of lignocellulosic structures to sugars were also analyzed and described, and reaction orders of 1 (LHW), 3 (HTC), and their respective reaction rate equations were reported.

Quantifying the performances of SU-8 microfluidic devices: high liquid water tightness, long-term stability, and vacuum compatibility

Quantifying the performances of SU-8 microfluidic devices: high liquid water tightness, long-term stability, and vacuum compatibility

A study of the nonlinear dynamics inside the exoplanetary system Kepler-22 using MATLAB® software

Kepler is a discovery-class mission designed to determine the frequency of Earth-radius planets in and near the habitable zone of solar-type stars. A habitable zone of a star is defined as a range of orbits within which a rocky planet can support liquid water on its surface. The most intriguing question driving the search for habitable planets is whether they host life.
 The aim of this paper is to study the motion of a “test particle” inside the exoplanetary system Kepler-22. This system consists of a sun-like star, Kepler-22, and a terrestrial exoplanet, Kepler-22b. This exoplanet is situated in the habitable zone of its star. Kepler-22b is located about 180 pc from Earth in the constellation of Cygnus. It was discovered by NASA’s Kepler Space Telescope in December 2011 and the planet is about 2.4 times the radius of Earth. Scientists don't yet know if Kepler-22b has a rocky, gaseous or liquid composition.
 In this study, let’s derive Lagrange points and perform several numerical tests to discover different possible orbits around the star Kepler-22. From many numerical tests performed, it is also possible to found two tadpole orbits around the Lagrange points L4 and L5 and a tadpole orbit around the exoplanet Kepler-22b, which encircles the two Lagrange points L1, and L2. Some of these orbits are found in the habitable zone and others outside. We have also examined the possibility of the existence of an exomoon around the terrestrial exoplanet Kepler-22b. In this case we have considered the mass of this exomoon.
 The Circular Restricted Three-Body Problem is used in this study. If it is further assumed that the third body (for example a planet, satellite, an asteroid or just a “test particle”) travels in the same plane as the two larger bodies, then there is the Planar Circular Restricted Three-Body Problem

Are Northern Hemisphere boreal forest fires more sensitive to future aerosol mitigation than to greenhouse gas-driven warming?

Considerable interest exists in understanding how climate change affects wildfire activity. Here, we use the Community Earth System Model version 2 to show that future anthropogenic aerosol mitigation yields larger increases in fire activity in the Northern Hemisphere boreal forests, relative to a base simulation that lacks climate policy and has large increases in greenhouse gases. The enhanced fire response is related to a deeper layer of summertime soil drying, consistent with increased downwelling surface shortwave radiation and enhanced surface evapotranspiration. In contrast, soil column drying is muted under increasing greenhouse gases due to plant physiological responses to increased carbon dioxide and by enhanced melting of soil ice at a depth that increases soil liquid water. Although considerable uncertainty remains in the representation of fire processes in models, our results suggest that boreal forest fires may be more sensitive to future aerosol mitigation than to greenhouse gas-driven warming.

Study on the Relationship between GDL Wettability and Liquid Water Behavior in Polymer Electrolyte Fuel Cells

Liquid water that accumulates inside gas diffusion layers (GDL) prevents oxygen transport and degrades the performance of polymer electrolyte fuel cells (PEFCs). Therefore, improving the drainage of GDL is neccesary. One factor that directly affects drainage is the wettability of GDLs. In this study, the relationship between wettability of GDL and drainage was investigated through a numerical simulation using the volume of fluid (VOF) method. The simulation incorporated condensation model to mimic the actual operation of a PEFC. As a result of the simulation, it was found that condensation occurs near the catalyst layer (CL), and that liquid water accumulation develops from the vicinity of the CL side to the channel side. Simulations for different contact angles of θ contact = 60°, 90°, 110°, and 150° were performed, and showed that the liquid water volume inside the GDL decreased in the case of higher contact angle. In addition, we found that the hydrophobicity of the GDL promotes the movement of liquid water and hastened liquid-water discharge from the GDL surface. In the case of higher contact angle, the proportion of the gas-liquid interface in the GDL and its curvature were found to increase. Furthermore, the liquid water was discharged from greater number of pores on the GDL surface.

Molecular dynamics study on relaxation of supercooled liquid water at different cooling rates

The relaxation in supercooled liquids is a phenomena by which the thermodynamic system starts transforming from one state to other after losing its high end thermodynamic properties (i.e. density, potential energy, enthalpy, etc.) with a significant change. Since the relaxation phenomena is quite challenging to observe, specifically near the transition region of liquid water. Hence, the thermodynamic analysis for understanding the relaxation phenomena of liquid water in supercooled region from the high density liquid (HDL) state to low density amorphous (LDA) state are important from both fundamental and as well as applied perspectives. Therefore, we focused our study on performing thermodynamic analysis on the relaxation of super-cooled liquid water by using a monatomic water (mW) potential model with an isothermal-isobaric (NPT) molecular dynamics (MD) simulation technique at zero pressure under different cooling rates. In this work, we examine the relaxation in terms of root mean square (RMS) fluctuation of two and three-body potential energy of the maximum size of four coordinated cluster under different cooling rates. The predicted data over this study shows the independency of the cooling rate, where the relaxation of the liquid state of mW water results in a sharp irreversible drop in potential energy and large fluctuation in two and three body potential energy of the maximum size of four coordinated cluster. Further, we found the relaxation of liquid state of mW water associated with the sharp and continuous increase in the fraction of four coordinated particles as a function of temperature for different cooling rates. The predicted results of this study are consistent with the literature, which helps to understand the relaxation phenomena of mW water and other such thermodynamic systems more significantly.

Transferable Water Potentials Using Equivariant Neural Networks.

Machine learning interatomic potentials (MLIPs) have emerged as a technique that promises quantum theory accuracy for reduced cost. It has been proposed [J. Chem. Phys. 2023, 158, 084111] that MLIPs trained on solely liquid water data cannot accurately transfer to the vapor-liquid equilibrium while recovering the many-body decomposition (MBD) analysis of gas-phase water clusters. This suggests that MLIPs do not directly learn the physically correct interactions of water molecules, limiting transferability. In this work, we show that MLIPs using equivariant architecture and trained on 3200 liquid water structures reproduces liquid-phase water properties (e.g., density within 0.003 g/cm3 between 230 and 365 K), vapor-liquid equilibrium properties up to 550 K, the MBD analysis of gas-phase water cluster up to six-body interactions, and the relative energy and the vibrational density of states of ice phases. We show that potentials developed using equivariant MLIPs allow transferability for arbitrary phases of water that remain stable in nanosecond long simulations.

Process Modeling of Aerosol‐Cloud Interaction in Summertime Precipitating Shallow Cumulus Over the Western North Atlantic

AbstractProcess modeling of Aerosol‐cloud interaction (ACI) is essential to bridging gaps between observational analysis and climate modeling of aerosol effects in the Earth system and eventually reducing climate projection uncertainties. In this study, we examine ACI in summertime precipitating shallow cumuli observed during the Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE). Aerosols and precipitating shallow cumuli were extensively observed with in‐situ and remote‐sensing instruments during two research flight cases on 02 June and 07 June, respectively, during the ACTIVATE summer 2021 deployment phase. We perform observational analysis and large‐eddy simulation (LES) of aerosol effect on precipitating cumulus in these two cases. Given the measured aerosol size distributions and meteorological conditions, LES is able to reproduce the observed cloud properties by aircraft such as liquid water content (LWC), cloud droplet number concentration (Nc) and effective radius reff. However, it produces smaller liquid water path (LWP) and larger Nc compared to the satellite retrievals. Both 02 and 07 June cases are over warm waters of the Gulf Stream and have a cloud top height over 3 km, but the 07 June case is more polluted and has larger LWC. We find that the Na‐induced LWP adjustment is dominated by precipitation feedback for the 2 June precipitating case and there is no clear entrainment feedback in both cases. An increase of cloud fraction due to a decrease of aerosol number concentration is also shown in the simulations for the 02 June case.

Insights on seasonal solifluction processes in warm permafrost Arctic landscape using a dense monitoring approach across adjacent hillslopes

Solifluction processes in the Arctic are highly complex, introducing uncertainties in estimating current and future soil carbon storage and fluxes, and assessment of hillslope and infrastructure stability. This study aims to enhance our understanding of triggers and drivers of soil movement of permafrost-affected hillslopes in the Arctic. To achieve this, we established an extensive soil deformation and temperature sensor network, covering 48 locations across multiple hillslopes within a 1 km2 watershed on the Seward Peninsula, AK. We report depth-resolved measurements down to 1.8 m depth for May to September 2022, a period conducive to soil movement due to deepening thaw layers and frequent rain events. Over this period, surface movements of up to 334 mm were recorded. In general, these movements occur close to the thawing front, and are initiated as thawing reaches depths of 0.4–0.75 m. The largest movements were observed at the top of the south-east facing slope, where soil temperatures are cold (mean annual soil temperatures averaging −1.13 °C) and slopes are steeper than 15°. Our analysis highlights three primary factors influencing movements: slope angle, soil thermal conditions, and thaw depth. The latter two significantly impact the generation of pore water pressures at the thaw–freeze interface. Specifically, soil thermal conditions govern the liquid water content, while thaw depth influences both the height of the water column and, consequently, the pressure at the thawing front. These factors affect soil properties, such as cohesion and internal friction angle, which are crucial determinants of slope stability. This underscores the significance of a precise understanding of subsurface thermal conditions, including spatial and temporal variability in soil temperature and thaw depth, when assessing and predicting slope instabilities. Based on our observations, we developed a factor of safety proxy that consistently falls below the triggering threshold for all probes exhibiting displacements exceeding 50 mm. This study offers novel insights into patterns and triggers of hillslope movements in the Arctic and provides a venue to evaluate their impact on soil redistribution.