scholarly journals Winter regime of temperature and snow accumulation as a factor of ground freezing depth variations

2020 ◽  
Vol 163 ◽  
pp. 01005 ◽  
Author(s):  
Denis Frolov
Keyword(s):  
Phase Transition ◽  
Snow Cover ◽  
Heat Conductivity ◽  
Meteorological Data ◽  
Snow Accumulation ◽  
Frozen Ground ◽  
Good Correspondence ◽  
Ground Freezing ◽  
Meteorological Observatory ◽  
Freezing Depth

The observations of ground freezing depth in the conditions of bare soil and under natural cover have been carried out at the sites of meteorological observatory of Lomonosov Moscow State University since the observatory’s foundation in 1954. For estimation of role of snow cover in variations of ground freezing depth the calculations of ground freezing depth were conducted using the meteorological data on air temperature and snow thickness for winter seasons of 2011/12-2018/19. The calculating scheme for ground freezing is constructed on the 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 the basis of Fourier law as a product of heat conductivity and temperature gradient. It is supposed, that the temperature changes in each media linearly. The comparison of calculated and observed values of ground freezing indicates good correspondence.

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

2020 ◽  
Vol 164 ◽  
pp. 01017 ◽  
Author(s):  
Denis Frolov
Keyword(s):  
Phase Transition ◽  
Snow Cover ◽  
Air Temperature ◽  
Heat Conductivity ◽  
Meteorological Data ◽  
Moscow Region ◽  
Observation Data ◽  
Frozen Ground ◽  
Ground Freezing ◽  
Freezing Depth

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.

scholarly journals 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

2020 ◽  
Vol 10 (2) ◽  
pp. 86-90 ◽  
Author(s):  
D. M. Frolov
Keyword(s):  
Snow Cover ◽  
Ground Surface ◽  
State University ◽  
Good Correspondence ◽  
Ground Freezing ◽  
Meteorological Observatory ◽  
Freezing Depth ◽  
Estimation Scheme ◽  
Cover Thickness ◽  
Moscow State University

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.

scholarly journals Calculation scheme of ground freezing depth in Terskol

2021 ◽  
Vol 135 (2) ◽  
pp. 7-13
Author(s):  
D.M. Frolov ◽  
Keyword(s):  
Phase Transition ◽  
Snow Cover ◽  
Calculation Scheme ◽  
Frozen Ground ◽  
Ground Freezing ◽  
Geotechnical Structures ◽  
Freezing Depth ◽  
Layer Medium ◽  
The Heat Balance

During the construction of avalanche-retaining geotechnical structures in mountainous areas comes up the problem of fixing and stability of these structures in conditions of seasonal and/or long-term freezing of the ground. This paper evaluates the influence of snow cover and air temperature on the depth of freezing and soil stability based on the developed calculation scheme for the winter seasons 2015/16-2019/20 in the Elbrus region. The calculation scheme was based on the problem of thermal conductivity of a three-layer medium (snow, frozen, and thawed soil) with a phase transition at the boundary. The heat balance equation included the energy of the phase transition, the inflow of heat from the thawed ground and the outflow to the frozen ground, and, in the presence of snow cover, through it to the atmosphere.

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

2021 ◽  
Author(s):  
Denis Frolov
Keyword(s):  
Thermal Conductivity ◽  
Snow Cover ◽  
Air Temperature ◽  
Winter Season ◽  
Moscow Region ◽  
Frozen Ground ◽  
Ground Freezing ◽  
Meteorological Observatory ◽  
Freezing Depth ◽  
Cover Thickness

<p>According to consdidered influence of snow cover thickness and air temperature on variations of ground freezing depth at the site of meteorological observatory of Moscow State University and also according to the data of observatories in the Moscow region it is expected to make conclusions about the impact of the urban heat island to a ground freezing depth in Moscow region. For this purpose, the values of the maximum ground freezing depth were analyzed for MSU meteorological observatory and for the weather stations of the Moscow region: Kolomna, Mozhaisk and Sukhinichi. And since not always the data of actual observations are avaliable, for these weather stations the calculated values of the maximum ground freezing depth were obtained. The calculations were performed according to the previously developed calculation scheme, based on the problem of thermal conductivity of a three-layer medium (snow, frozen and thawed ground) with a phase transition at the boundary. The heat balance equation included the energy of the phase transition, the inflow of heat from the thawed ground and the outflow to the frozen ground and, in the presence of snow cover, through it to the atmosphere. The heat flow was calculated according to Fourier's law as the product of the thermal conductivity and the temperature gradient. It was assumed that the temperature in each medium varies linearly. For snow cover and frozen ground, the formula of thermal conductivity of a two-layer medium was used. The obtained calculated values were compared with the actual values of the ground freezing depth. The coefficients R<sup>2</sup> of the reliability of the linear trend line approximation when comparing the calculated and actual values for Moscow and the Moscow region were at the level of 0.6-0.7. The maximum ground freezing depth in Moscow and in the Moscow region in the same years may differ by an average of 10 cm. This confirms that the designed scheme well describes ground freezing depth based on data on air temperature and snow cover thickness and can be used to model the underground heat island of the Moscow region. In report it is also supposed to present the results of the recent years observations of snow cover and freezing depth variations in Moscow and the Moscow region. The past  2020 year is considered as the warmest in the entire history of observations according to the MSU Meteorological Observatory for Moscow, according to the Hydrometeorological Center of Russia for the whole of Russia and according to the Copernicus Climate Change Service (C3S) for the entire Globe. So the winter season of 2019/20 in Moscow region was also unusually warm, and therefore in the winter season of 2019/20 there was very little snow in the Moscow region. However, the warm summer of 2020 resulted in one of the lowest summer values of sea ice extent in the Arctic and, as a result, abnormally strong minimum temperatures and heavy snowfall in the winter of 2020/21 in Eurasia and Moscow. The work was done in a frame of state topic AAAA-A16-116032810093-2.</p>

scholarly journals Peculiarities of weather and snow accumulation conditions in Moscow region in winter period 2019/2020

2020 ◽  
Vol 164 ◽  
pp. 01018 ◽  
Author(s):  
Denis Frolov
Keyword(s):  
Snow Cover ◽  
Temperature Regime ◽  
Snow Accumulation ◽  
Moscow Region ◽  
Winter Period ◽  
Ground Freezing ◽  
Freezing Depth

The study of weather and snow accumulation conditions is important because for example on basis of knowledge on temperature regime and accumulation peculiarities of snow cover the ground freezing depth calculations are performed. So the results of study of peculiarities of weather and snow accumulation conditions in Moscow region for winter period 2019/2020 are presented in the paper. The comparison of these data for this winter period with the previous winter periods and the long-term averaged values is also done.

scholarly journals Event-driven deposition: a new paradigm for snow-cover modelling in Antarctica based on surface measurements

2012 ◽  
Vol 6 (5) ◽  
pp. 3575-3612 ◽  
Author(s):  
C. D. Groot Zwaaftink ◽  
A. Cagnati ◽  
A. Crepaz ◽  
C. Fierz ◽  
M. Lehning ◽  
...  
Keyword(s):  
Snow Cover ◽  
Meteorological Data ◽  
Lower Boundary ◽  
Snow Accumulation ◽  
New Paradigm ◽  
Event Driven ◽  
Total Magnitude ◽  
Antarctic Snow ◽  
Strong Winds ◽  
The Antarctic

Abstract. Antarctic surface snow is studied by means of continuous measurements and observations over a period of 3 yr at Dome C. Snow observations include precipitation, daily records of deposition and erosion, snow temperatures at several depths, and snow profiles. Together with meteorological data from automatic weather stations, this forms a unique and complete dataset of snow conditions on the Antarctic Plateau. Large differences in snow amounts and density exist between precipitation measured 1 m above the surface and deposition on the surface. We then used the snow-cover model SNOWPACK to simulate the snow-cover evolution for different deposition parameterizations. The main adaptation of the model described here is a new event-driven accumulation scheme. The scheme assumes that snow is added to the snow cover permanently only for periods of strong winds. This assumption followed from the comparison between precipitation observations and daily records of changes in snow height, which showed that over a period of 235 days there was precipitation on 40% and deposition on 25% of the days, but precipitation accompanied by deposition on 14% of the days only. This confirms that precipitation is not necessarily the driving force behind snow height changes. A comparison of simulated snow height to stake farm measurements over 3 yr showed that we underestimate the total accumulation by about 64%, when the total snow deposition is constrained by the precipitation measurements. This is because the precipitation measured above the surface and used to drive the model, even though comparable to ECMWF forecasts in its total magnitude, should be seen as a lower boundary of accumulation. As a result of the new deposition mechanism, we found a good agreement between model results and measurements of snow temperatures and recorded snow profiles. In spite of the underestimated accumulation, the results strongly suggest that we can obtain quite realistic simulations of the Antarctic snow cover by the introduction of event-driven snow accumulation.

scholarly journals Model of the influence of snow cover on soil freezing

2000 ◽  
Vol 31 ◽  
pp. 417-421 ◽  
Author(s):  
N. I. Osokin ◽  
R. S. Samoylov ◽  
A.V. Sosnovskiy ◽  
S. A. Sokratov ◽  
V. A. Zhidkov
Keyword(s):  
Snow Cover ◽  
Soil Depth ◽  
Negative Temperature ◽  
Snow Accumulation ◽  
Frozen Soil ◽  
Soil Freezing ◽  
Soil Frost ◽  
Wide Range ◽  
Freezing Depth ◽  
Good Agreement

AbstractA mathematical model of snow-cover influence on soil freezing, taking into account the phase transition layer, water migration in soil, frost heave and ice-layer formation, has been developed. The modeled results are in good agreement with data observed in natural conditions. The influence of a possible delay between the time of negative temperature establishment in the air and the beginning of snow accumulation, and possible variations of the thermophysical properties of snow cover in the wide range previously reported were investigated by numerical experiments. It was found that the delay could change the frozen-soil depth up to 2–3 times, while different thermophysical characteristics of snow changed the resulting freezing depth 4–5 times.

Influence of Snowcover Development and Ground Freezing on Cation Loss from a Wetland Watershed during Spring Runoff

1985 ◽  
Vol 42 (12) ◽  
pp. 1979-1985 ◽  
Author(s):  
D. C. Pierson ◽  
C. H. Taylor
Keyword(s):  
Snow Cover ◽  
Early Spring ◽  
Snow Accumulation ◽  
Hydrogen Ion ◽  
Soil Frost ◽  
Spring Runoff ◽  
South Central ◽  
Ground Freezing ◽  
Calcium Magnesium ◽  
Small Wetland

Cation and water export were monitored from a small wetland watershed in south-central Ontario during spring runoff for two years with very different sequences of snowpack development. In 1977, a persistent snow cover developed in the watershed by 1 December, and snow accumulation was near normal for this region. In 1980, persistent snow cover did not develop until mid-January, and the final snowpack was well below average. Between years, major differences in the timing of ion export were found for calcium, magnesium, and sodium, ions which appear to be associated with the watershed's soils. Conversely, potassium, a cation not as strongly associated with soil ion sources, showed temporal patterns of export which were similar in timing during the two years. We hypothesize that concrete soil frost, which developed in 1980 as a consequence of the late-developing snow cover, strongly influenced the timing of ion export by isolating early spring runoff from the watershed's soils. Streamwater hydrogen ion concentrations decreased rapidly during the first week of spring runoff in 1980, indicating that hydrogen ion export was increased by a similar mechanism. We suggest that in poorly buffered systems, the formation of concrete soil frost may lead to significant increases in hydrogen ion export during spring snowmelt.

scholarly journals Change in snow depletion pattern in a river basin of Arunachal Pradesh under projected climatic scenarios

2017 ◽  
Vol 19 (2) ◽  
pp. 199-210
Keyword(s):  
Snow Cover ◽  
Meteorological Data ◽  
Snow Accumulation ◽  
High Mountain ◽  
Present Climate ◽  
Arunachal Pradesh ◽  
Temperature And Precipitation ◽  
Depletion Curve ◽  
Climatic Scenarios ◽  
The Impact

<p>Snow depletion curves (SDCs) are important in hydrological studies for predicting snowmelt generated runoff in high mountain catchments. The present study deals with the derivation of the average snow depletion pattern in the Mago basin of Arunachal Pradesh, which falls in the eastern Himalayan region and the generation of climate affected SDCs in future years (2020, 2030, 2040, and 2050) under different projected climatic scenarios. The MODIS daily snow cover product at 500m resolution from both the Aqua and Terra satellites was used to obtain daily snow cover maps. MOD10A1 and MYD10A1 images were compared to select cloud free or minimum cloud image to obtain the temporal distribution of snow cover area (SCA). Snow accumulation and depletion patterns were obtained by analysing SCA at different days. For most of the years, two peaks were observed in the SCA analysis. The conventional depletion curve (CDC) representing present climate was derived by determining and interpolating the SCA from cloud-free (cloud&lt;5%) images for the selected hydrological year 2007. The investigation shows that the SCA was highest in February and lowest in May. Ten years meteorological data were used to normalize the temperature and precipitation data of the selected hydrological year (2007) to eliminate the impact of their yearly fluctuations on the snow cover depletion. The temperature and precipitation changes under four different projected climatic scenarios (A1B, A2, B1, and IPCC Commitment) were analysed for future years. Changes in the cumulative snowmelt depth with respect to the present climate for different future years were studied by a degree-day approach and were found to be highest under A1B, followed by A2, B1, and IPCC Commitment scenarios. It was observed that the A1B climatic scenario affected the depletion pattern most, making the depletion of snow to start and complete faster than under different scenarios. Advancing of depletion curve for different future years was found to be highest under A1B and lowest under IPCC Commitment scenarios with A2 and B1 in-between them.</p>

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