Thick Snow Cover Research Articles

Snowpack-stored atmospheric surface-active contaminants traced with snowmelt water surface film rheology

The aim of the study was to quantify the adsorptive and thermo-elastic properties of snowmelt water surface films and their spatial-temporal evolution with snowpack structure characteristics and the entrapped surface-active organic composition. Surface pressure–area (π-A)T isotherms, surface pressure-temperature (π-T)A isochors, and stress–relaxation (π-t) measurements were performed using a Langmuir trough system on snowmelt water samples collected in a large-scale field studies performed at several industrialized and rural Tricity (Gdansk, Poland) areas at various environmental conditions and subsequent stages of the snowpack melting progress. Since the snow-melted water composition and concentrations of surface active organic matter fractions therein are largely undetermined, the force-area isotherm scaling formalisms (2D virial equation and 2D film scaling theory of polymeric films) were adapted to the complex mixture of surfactants. The surface film parameters and their spatial and temporal evolution turned out to be unequivocally related to principal signatures of the film-forming materials: surfactant concentrations (π, Alim), surface activity (Eisoth, |E|), film material solubility (R), surface material miscibility and 2D architecture complexity (y, βs), molecular thermal mobility (πk), and a timescale of the relaxation processes within the film (τi, |E|). Moreover, the parameters appeared to be correlated with snowpack structure characteristics (snow density ρ, specific snow area SSA, snow cover thickness), sample age time, and anthropogenic atmospheric contamination pressure source locations. In particular, Eisoth was found to be related to ρ and SSA, while R correlated with the solubility of film-forming organics which turned out to be long-chain fatty acids; similarly, spatial profiles of Eisoth revealed the peak values next to the areas being under a severe anthropogenic air pollution pressure. Snowmelt water films stand for a structurally heterogeneous (y > 10) interfacial system where several transition processes of differentiated time-scales (relaxation times from 7 to 63 s) took place leading to the apparent surface viscoelasticity. To sum up, the established surface rheological parameters could serve as novel indicators, based solely on physical attributes, allowing to follow the snowpack evolution, and its melting polymorphism in order to test or improve the existing snow-entrapped organics release models based on chemical analyses. The cross-correlation functional dependences of practical value remain to be established on the larger data set.

Подходы к определению толщины снежного покрова с использованием лазерного сканирования

The task of determining the snow cover thickness with high accuracy (more than 20 cm), with high level of detail in large areas, is important when planning large business projects related to the sustainable development of the territory (ski clusters, mining enterprises, modeling river flows to regulate hydropower plants). At the same time, there is a demand to evaluate tens and hundreds of square kilometers of the territory, sometimes with a very rugged terrain and vegetation. Using generally adopted direct measurement methods acceptable for limited areas is impossible in this case. The general requirements for the desired methodology are as follows

Frost Quakes: Crack Formation by Thermal Stress

AbstractFractures in frozen soils (frost quakes) can cause damage to buildings and other infrastructure, but their formation mechanisms remain poorly understood. A methodology was developed to assess thermal stress on soil due to changes in climate and weather conditions and to investigate the connection between thermal stress and frost quakes in central Finland due to brittle fracturing in uppermost soils. A hydrological model was used to simulate snow accumulation and melt, and a soil temperature model was used to simulate soil temperature at different depths beneath the snow pack. The results of modeling, together with measurements of air temperature, snow cover thickness, and soil temperature, were used to calculate temporal variations in thermal stress in soil. We show that frost quakes occur when thermal stress caused by a rapid decrease in temperature exceeds fracture toughness and strength of the soil‐ice mixture. We compared calculated thermal stress on soil, critical stress intensity factor, and a seismogram recorded in a suburban region in central Finland. Our results suggest that this methodology can be used to predict thermal stresses on soil and identify stress values that may lead to fractures of frozen soils, that is, frost quakes.

Preliminary Results of an Experiment to Determine the Thickness of Snow Cover Using Ground Penetrating Radar and a Laser Rangefinder

The article discusses the combination of a ground penetrating radar (GPR) with a laser rangefinder to determine the snow cover thickness, an experiment is described in accordance with the proposed methodology and a comparative analysis of the data obtained is carried out. The purpose of the proposed development of the combined method is to improve the accuracy of snow cover depth determination. Many tasks require high spatial resolution both in the horizontal coordinate and in the depth of the snow cover, since local excess of its critical level can lead to irreversible consequences. Such a situation can arise, for example, when avalanches come down in mountainous areas or when roofs of a large area collapse when snow accumulates on them. The accuracy of the snow depth determination obtained in the experiment is ∼ 10 cm and the resolution along the horizontal coordinate is ∼ 5 cm. The predicted distance based on the equipment used is about 500 meters. The proposed method can be used for determining the amount of snow on roofs of buildings and structures, as well as in predicting the descent of avalanches, and in search for hidden objects under the snow in emergency situations.

Linking tundra vegetation, snow, soil temperature, and permafrost

Abstract. Connections between vegetation and soil thermal dynamics are critical for estimating the vulnerability of permafrost to thaw with continued climate warming and vegetation changes. The interplay of complex biophysical processes results in a highly heterogeneous soil temperature distribution on small spatial scales. Moreover, the link between topsoil temperature and active layer thickness remains poorly constrained. Sixty-eight temperature loggers were installed at 1–3 cm depth to record the distribution of topsoil temperatures at the Trail Valley Creek study site in the northwestern Canadian Arctic. The measurements were distributed across six different vegetation types characteristic for this landscape. Two years of topsoil temperature data were analysed statistically to identify temporal and spatial characteristics and their relationship to vegetation, snow cover, and active layer thickness. The mean annual topsoil temperature varied between −3.7 and 0.1 ∘C within 0.5 km2. The observed variation can, to a large degree, be explained by variation in snow cover. Differences in snow depth are strongly related with vegetation type and show complex associations with late-summer thaw depth. While cold winter soil temperature is associated with deep active layers in the following summer for lichen and dwarf shrub tundra, we observed the opposite beneath tall shrubs and tussocks. In contrast to winter observations, summer topsoil temperature is similar below all vegetation types with an average summer topsoil temperature difference of less than 1 ∘C. Moreover, there is no significant relationship between summer soil temperature or cumulative positive degree days and active layer thickness. Altogether, our results demonstrate the high spatial variability of topsoil temperature and active layer thickness even within specific vegetation types. Given that vegetation type defines the direction of the relationship between topsoil temperature and active layer thickness in winter and summer, estimates of permafrost vulnerability based on remote sensing or model results will need to incorporate complex local feedback mechanisms of vegetation change and permafrost thaw.

Peculiarities of weather and ground freezing conditions in Siberia and Russian Arctic in winter and spring period of 2019/2020

As a reason of anomalous warm winter 2019/2020 in Russia, as well as in Europe and USA along with the global warming is considered a non-typical situation in Arctic, where the extremely stable area of low pressure in the vicinity of North Pole was present during long time period and which does not let the cold air masses to move away from its borders. Such situation lead to the consequence, that on the most of the territory of Russia, USA, Northern Europe and Eastern Canada the temperature of winter months was on a few degrees more than usual. Due to these warm winter months 2019/2020, largely increasing in recent decade’s amount of snow and snow cover thickness and hot spring months 2020 in Siberia and Russian Arctic the winter ground freezing was not very intensive and active layer thickness at the beginning of the summer was rather high. This led to the oil tank construction damage in Norilsk on 29 May 2020 due to the instability of the basement and catastrophic oil spill into the river happened.

The effect of snow covers properties and air temperature on the ice freezing thickness near Yakutsk

This study is devoted to the possible Yakutsk Lena–river automobile and railway bridge construction and estimation of icing and ice blockage formation possibility variation. So, according to developed algorithm and calculating scheme the calculations of ice freezing thickness variations for observation site of Yakutsk Lena-river hydrological station were performed on basis of meteorological data on air temperature and snow cover thickness for winter periods of 1980/81-2018/19. The comparison of calculated and available in open access observation data on ice freezing thickness for these winter periods was also conducted and the coefficient of correlation of equal 0.7-0.8 for them was stated. The calculating scheme for ice freezing is constructed on basis of two-layer media heat conductivity problem (snow cover, ice) with phase transition on the boundary of ice and unfrozen water. Heat balance equation includes phase transition energy on the interface and outflow of heat through ice and snow cover into the atmosphere. The heat flux is calculated on basis of Fourier law as a product of heat conductivity and temperature gradient. It is supposed, that temperature changes in each media linearly.

Fast Ice Prediction System (FIPS) for land-fast sea ice at Prydz Bay, East Antarctica: an operational service for CHINARE

AbstractA Fast Ice Prediction System (FIPS) was constructed and is the first regional land-fast sea-ice forecasting system for the Antarctic. FIPS had two components: (1) near-real-time information on the ice-covered area from MODIS and SAR imagery that revealed, tidal cracks, ridged and rafted ice regions; (2) a high-resolution 1-D thermodynamic snow and ice model (HIGHTSI) that was extended to perform a 2-D simulation on snow and ice evolution using atmospheric forcing from ECMWF: either using ERA-Interim reanalysis (in hindcast mode) or HERS operational 10-day predictions (in forecast mode). A hindcast experiment for the 2015 season was in good agreement with field observations, with a mean bias of 0.14 ± 0.07 m and a correlation coefficient of 0.98 for modeled ice thickness. The errors are largely caused by a cold bias in the atmospheric forcing. The thick snow cover during the 2015 season led to modeled formation of extensive snow ice and superimposed ice. The first FIPS operational service was performed during the 2017/18 season. The system predicted a realistic ice thickness and onset of snow surface melt as well as the area of internal ice melt. The model results on the snow and ice properties were considered by the captain of R/VXuelongwhen optimizing a low-risk route for on-ice transportation through fast ice to the coastal Zhongshan Station.

Thermodynamics of Fast Ice off the Northeast Coast of Greenland (79°N) Over a Full Year (2012–2013)

AbstractNorske Øer Ice Barrier (NØIB) is a vast region of fast ice off northeast Greenland. To understand its thermodynamics, an ice mass balance buoy (IMB) was deployed in late August 2012. The IMB operated for a full year, providing unique year‐round observations of air, snow, ice, and upper ocean. Here, we examine atmospheric conditions and snow and sea ice evolution, derive the ocean heat flux at the deployment site, and investigate the effect of snow on the sea ice mass balance. Although an extremely low surface air temperature of −52°C was recorded at the IMB site, the sum of freezing‐degree days (4,848 K·d) is similar to that in the central Arctic. The maximum snow depth 0.73 m (on 29 May 2013, when ice was 2.19 m thick) is thicker than typically observed on level Arctic landfast ice and drift ice, and thick snow appears common in this region. Ocean heat flux was large in autumn and early winter (>7 W m−2), attributed in part to local solar heating of surface waters in summer and advected ocean heat later in the year. The combination of high ocean heat flux and thick snow resulted in a net loss of ice at the ice bottom over the year. A one‐dimensional sea ice model suggests that the thick snow cover limits bottom ice growth significantly. The heavy snow load could potentially have contributed 0.29 m snow ice; however, we cannot unambiguously prove this happened.

Snow cover as a morphogenic agent determining ground climate, landforms and runoff in the Valdecebollas massif, Cantabrian Mountains

Snowfalls are important meteorological events affecting the physical environment of the Cantabrian Mountains. This work analyzes the effects of snow on several elements such as relief, landforms, ground climate and snowmelt waters. The ground thermal regime and associated parameters were studied using temperature data loggers and satellite images and were described in combination with observed geomorphological processes and landforms. A geomorphological map was drawn up and trends in climate patterns and runoff were calculated. Ground temperature monitoring in warm years is not optimal, though allow to know the limit conditions for developing cold processes. Results show that geomorphological processes are not significant and that solifluction deriving from snowmelt, is the only active process in years without freeze or with thick snow cover. Snowfall evolution in recent decades in correlation with flow water and climate features provide the certainty that snow distribution also affects efficacy in runoff generation and moves the flow peak in rivers due to early snowmelt.

Effect of hyaloclastite breccia boulders on meso-scale periglacial-aeolian landsystem in semi-arid Antarctic environment, James Ross Island, Antarctic Peninsula

In this study we aim to describe the processes leading to the creation of a specific periglacial and aeolian landsystem, which evolves around the hyaloclastite breccia boulders on James Ross Island, north-eastern Antarctic Peninsula. These boulders were deposited as a result of the Late Holocene advance of Whisky Glacier, forming a well-developed boulder train approximately 5-km long, stretching from Whisky Glacier moraine to Brandy Bay. The combination of ground temperature monitoring, snow cover measurements, grain size analysis and field survey were used to quantify and understand the interplay of periglacial and aeolian processes leading to the formation of the specific meso-scale landsystem around the boulders. The ground temperature probes were installed during January 2017 in the vicinity of two selected boulders. The two study sites, at Monolith Lake (large boulder) and Keller Stream (smaller boulder), were also fitted with snow stakes and trail cameras. An automatic weather station (AWS) on the Abernethy Flats, located approximately two kilometres to the north-west, was used as a reference site for ground temperature and snow cover thickness. The hyaloclastite breccia boulders act as obstacles to wind and trap wind-blown snow, resulting in the formation of snow accumulations on their windward and lee sides. These accumulations affect ground thermal regime and lead to the transport of fine particles by meltwater from the snow during the summer season. The snow cover also traps wind-blown fine sand resulting in the formation of fine-grained rims on the windward and lee sides of the boulders after the snow has melted. Furthermore, the meltwater affects ground moisture content, creating favourable, but spatially limited conditions for colonisation by mosses and lichens.

Spatial Differentiation of the Maximum River Runoff Synchronicity in the Warta River Catchment, Poland

Based on daily flows recorded in the period 1971–2010, the synchronous occurrence of the annual (AMAXq), winter (WMAXq), and summer (SMAXq) maximum specific runoffs in 39 sub-catchments of the Warta River catchment (WRC) in Poland was analyzed. First, trends in the flows were detected using the non-parametric Mann–Kendall (M-K) test. Then, the degree of the synchronous and asynchronous occurrences of the maximum specific runoffs (MAXq) in respective sub-catchments in relation to the Gorzów Wielkopolski gauge closing the WRC was calculated. Finally, the reasons for the detected spatial and temporal differences were discussed. The study revealed a noticeable variability of the analyzed parameters. The highest synchronicity of AMAXq and WMAXq in relation to the closing Gorzów Wielkopolski gauge was revealed in the man-made Kościański and Mosiński canals and in the sub-catchments of the Noteć, Wełna, and lower Prosna rivers. While compared to AMAXq and WMAXq, the summer maxima showed relatively lower degrees of synchronicity, an increase in the synchronous occurrence of SMAXq in the southern part of WRC, and a decrease in its central part were identified. It was concluded that the stronger synchronicity of WMAXq resulted from the nival regime of the investigated rivers. Consequently, the annual maxima were most often associated with the winter half-year. The detected differences of synchronicity of the annual and seasonal runoffs are conditioned by climate, more specifically by the course of winter and resulting from it snow cover thickness, and also the amount and intensity of rainfall in summer.

Effect of freezing and thawing on nutrient content of soft rock

There are few studies on the effects of freeze-thaw on soil nutrients and soil enzymes, which are directly related to soil fertility and soil biological activity. In the past, the research mainly focused on the nitrogen and phosphorus cycle in the growing period of soil, but more and more studies have found that the non growing season in winter and the change of snow cover thickness caused by global warming affect the nitrogen and phosphorus cycle in the soil The influence of environment on the interannual scale can not be ignored. After the freeze-thaw cycle, the total nitrogen content of the soil did not change significantly, compared with that before the freeze-thaw cycle, the available potassium content of the arsenic sandstone increased, but not significantly; the available phosphorus content of the soil in the freeze-thaw cycle decreased.

Effect of frequent winter warming events (storms) and snow on sea-ice growth – a case from the Atlantic sector of the Arctic Ocean during the N-ICE2015 campaign

AbstractWe examine the relative effect of warming events (storms) and snow cover on thermodynamic growth of Arctic sea ice in winter. We use a 1-D snow and ice thermodynamic model to perform sensitivity experiments. Observations from the winter period of the Norwegian young sea ICE (N-ICE2015) campaign north of Svalbard are used to initiate and force the model. The N-ICE2015 winter was characterized by frequent storm events that brought pulses of heat and moisture, and a thick snow cover atop the sea ice (0.3–0.5 m). By the end of the winter, sea-ice bottom growth was negligible. We show that the thermodynamic effect of storms to the winter sea-ice growth is controlled by the amount of snow on sea ice. For 1.3 m initial ice thickness, the decrease in ice growth caused by the warming events ranged from −1.4% (for 0.5 m of snow) to −7.5% (for snow-free conditions). The decrease in sea-ice growth caused by the thick snow (0.5 m) was more important, ranging from −17% (with storms) to −23% (without storms). The results showcase the critical role of snow on winter Arctic sea-ice growth.

An Improved UWB Microwave Radar for Very Long-Range Measurements of Snow Cover

We present an ultrawideband (UWB) frequency-modulated (FM) microwave radar instrument capable of preserving cm-scale vertical resolution from a very long range (verified up to ~6 km). The system can operate either as a conventional continuous-wave FM radar (2-18 GHz) or in time-delayed stretch processing mode (2-14 GHz), providing high sensitivity, fine range resolution, and very low-range sidelobes. We present an overview of the system and laboratory test results to validate its performance. As a practical demonstration of its capabilities, we tested the system's ability to map snow cover thickness on the Arctic marine ice. We present sample results from airborne measurements carried out at altitudes between ~500 m and ~6 km above the ground level onboard a long-range fixed-wing platform.

Model and algorithms of interaction of the snow avalanche with the stirrable and destructible obstructions

A model for studying the movement of avalanche-hazardous snow masses based on the method of smoothed particles is presented. This approach has been shown to be most appropriate in modelling environments prone to fragmentation. The impact of the snow avalanche on vehicles and the dependence of the affecting factors on the thickness of the snow cover and the terrain have been investigated. It has been found that with snow cover thickness up to 0.5 m, avalanche does not lead to loss of vehicle controllability. The results of the modelling at a qualitative level coincide with the real effects of the avalanche on the vehicle, which confirms the adequacy of the model developed.

Calculations of ground freezing depth under bare and covered with the snow cover ground surface for the site of the meteorological observatory of Lomonosov Moscow State University for winter periods of 2011/12-2017/18

The calculating scheme for estimation of ground freezing depth under bare and covered with the snow cover ground surface on basis of air temperature and snow cover thickness is constructed and the example of calculations is performed for the site of the meteorological observatory of Lomonosov Moscow State University for winter periods of 2011/12-2017/18. The comparison of results of estimation scheme and observations indicated good correspondence.

Retrieving Snow Depth Information From AMSR2 Data for Qinghai–Tibet Plateau

Passive microwave data have been extensively used for snow depth (SD) inversion, but their accuracy has large error in the Qinghai–Tibet Plateau (QTP). Thus, there is still room for improvement in regional SD inversion. Ground-measured SD data combined with elevation, longitude, and land cover data were used to develop a multifactor SD inversion model based on Advanced Microwave Scanning Radiometer 2 (AMSR2) over the QTP. The SD inversion model and the AMSR2 SD product were validated and compared using the meteorological stations and ground-measured SD over the QTP at the same time. The results show that the root-mean-square error (RMSE) of the novel model developed in this study is approximately 5 cm, which is much better than the accuracy of the AMSR2 SD product (11–13 cm) released by the Japan Aerospace Exploration Agency. When the ground-measured SD is less than 30 cm, the RMSE and the mean absolute error of the developed model are below 7 and 6 cm, respectively, and the BIAS is approximately 1 cm. The SD inversion results are poor in the western part of the plateau due to the complex terrain and thick snow cover, and its RMSE is greater than 15 cm. In conclusion, this novel SD inversion model is more applicable and accurate than the AMSR2 SD products.

Szorstkość pokrycia terenu jako źródło błędu metody SfM zastosowanej do rekonstrukcji zasięgu pokrywy śnieżnej = Terrain roughness as a source of error with the SfM method applied to the reconstruction of snow cover extent

A comparison between errors associated with snow-cover reconstruction performed by processing aerial imagery acquired by a visible-light camera mounted on board unmanned aerial vehicles, one the one hand; and average terrain roughness, on the other, revealed a dependent relationship between these variables. A stronger correlation is noted for two of the studied test areas (Polana Izerska and Krobica, both located in SW Poland), as opposed to the remaining site (Drożyna, SW Poland). In particular, correlations are noticeable where the analysis is performed in moving windows. It is typical for terrain where depth of snow cover is reconstructed with severe errors to reveal a high degree of roughness caused by single trees, clumps of trees or buildings. Ambiguous results are obtained for the Drożyna research field. While the character of the dependent relationship there seems consistent with results for the remaining sites, the strength is low. The lower values for the correlation coefficient were driven by observations for which errors were found to be high while values for the Topographic Ruggedness Index were at the same time low. This effect can be explained by reference to the specific nature of the area reconstructed, which is much transformed by human activity. It proves difficult to reconstruct the depth of snow cover on roads properly, as these are either partially cleared or snow or characterised by its loss in the course of melting. Low thickness of snow cover is thus found to be a constrained when it comes to the generation of accurate reconstructions of the depth of snow cover. This is in fact a finding in agreement with what has been reported by other authors.

Influence of air temperature and snow cover accumulation regimes on ground freezing depth variations in Moscow region

According to developed algorithm and calculating scheme the calculations of ground freezing depth variations for observation sites of meteorological stations of Moscow region (Mozhaysk, Kolomna) were performed on basis of meteorological data on air temperature and snow cover thickness for winter periods of 1988/89-2018/19. The comparison of calculated and available in open access observation data on ground freezing depth for these winter periods was also conducted and indicated good correspondence. The calculating scheme for ground freezing is constructed on basis of three layer media heat conductivity problem (snow cover, frozen and thawed ground) with phase transition on the boundary of frozen and unfrozen ground. Heat balance equation includes phase transition energy, inflow of heat from unfrozen ground and outflow to frozen ground, snow cover and atmosphere. The heat flux is calculated on basis of Fourier law as a product of heat conductivity and temperature gradient. It is supposed, that temperature changes in each media linearly.