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 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.

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 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.

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.

The Influence of Uncertainty in Air Temperature and Albedo on Snowmelt

1991 ◽  
Vol 22 (2) ◽  
pp. 95-108 ◽  
Author(s):  
G. Blöschl
Keyword(s):  
Snow Cover ◽  
Air Temperature ◽  
Meteorological Data ◽  
Model Parameters ◽  
Local Effects ◽  
Austrian Alps ◽  
Air Temperatures ◽  
Basin Scale ◽  
Simulation Results

Extrapolating meteorological data to the basin scale represents a major problem of spatial snowmelt modelling in alpine terrain. Within this study errors in air temperature introduced by regionalization are analyzed for the Sellrain region in the Austrian Alps. Albedo is simulated using a range of model parameters representing different snow cover conditions. The influence on snowmelt is assessed by simulating water equivalent at the site scale using estimated air temperatures and albedoes. Simulation results indicate that a bias in measured temperatures as produced by local effects may be significantly more important than interpolation errors. Uncertainty in albedo appears to affect snowmelt to a higher degree than air temperature.

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 Análise comparativa da velocidade do vento e da temperatura do ar, entre dados gerados por reanálises meteorológicas e dados observacionais na região de Minas Gerais

2018 ◽  
Vol 40 ◽  
pp. 20
Author(s):  
Mauren Lucila Marques de Morais Micalichen ◽  
Nelson Luís da Costa Dias
Keyword(s):  
Wind Speed ◽  
Air Temperature ◽  
Meteorological Data ◽  
Reanalysis Data ◽  
Minas Gerais ◽  
Data Series ◽  
Continuous Series ◽  
Observation Data ◽  
Alternative Source ◽  
Wind Speed Data

The use of alternative sources of meteorological data has become increasingly common, making it possible to evaluate areas with no long or continuous series of meteorological data. In this context, the main objective of this study is to evaluate the performance of data series from the National Centers for Environmental Prediction / National Center for Atmospheric Research (NCEP/NCAR) for the state of Minas Gerais and verify the possible use of them in the absence of data observations of air temperature and wind speed. The analyzes were performed by comparing observation data from 17 meteorological stations and reanalysis data of the CFSR and CFSV2 models. From the results of the statistical analysis, it is observed that the air temperature reanalysis data presented a good performance in the region of study. However, wind speed data show a weak correlation. These results show that the air temperature data from these reanalyses have the potential to be used as an alternative source of data. Further studies are suggested regarding the use of wind speed data from these reanalyses.

Air temperature, snow cover, creep of frozen ground, and the time of ice-wedge cracking, western Arctic coast

1993 ◽  
Vol 30 (8) ◽  
pp. 1720-1729 ◽  
Author(s):  
J. Ross Mackay
Keyword(s):  
Snow Cover ◽  
Active Layer ◽  
Air Temperature ◽  
Thermal Stresses ◽  
Temperature Drop ◽  
Frozen Ground ◽  
Air Temperatures ◽  
Ice Wedge ◽  
Western Arctic ◽  
Arctic Coast

The time of ice-wedge cracking is examined for several sites with young and old ice wedges along the western Arctic coast. The correlation between sharp air temperature drops and ice-wedge cracking is highest where the snow cover is thin and least where the snow cover is thick. The favoured duration and rate of a temperature drop that results in cracking is about 4 days, at a rate of about 1.8°C/d. Such temperature drops have a minimal effect in cooling the top of permafrost wherever there is an appreciable snow cover. Since short duration temperature drops often result in ice-wedge cracking, the thermal stresses that trigger cracking probably originate more within the frozen active layer than at greater depth in permafrost. Although most ice wedges tend to crack during periods of decreasing air temperatures, about one third of those monitored have cracked during periods of increasing air temperatures. Long-term measurements show that the active layer and top of permafrost move differentially all year in a periodic movement. That is, creep of frozen ground occurs all year, irrespective of whether ice wedges crack or do not crack. The presence of a snow cover and the creep of frozen ground are two major factors that confound a simple application of conventional ice-wedge cracking theory to air temperature drops and the time of ice-wedge cracking.

scholarly journals A meteorological estimation of relevant parameters for snow models

1993 ◽  
Vol 18 ◽  
pp. 65-71 ◽  
Author(s):  
Y. Durand ◽  
E. Brun ◽  
L. Merindol ◽  
G. Guyomarc'h ◽  
B. Lesaffre ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Snow Cover ◽  
Real Time ◽  
Meteorological Parameters ◽  
Meteorological Data ◽  
Observation Data ◽  
Meteorological Observation ◽  
French Alps ◽  
Snow Model

Relevant meteorological parameters have been analyzed to provide boundary conditions in real time for an energy, mass and stratigraphical model of snow cover at locations surrounded by meteorological observation points. From the available observation data, this analysis provides hourly meteorological information on every Alpine massif for six different aspects at 300 m elevation intervals. A numerical snow model has been run with these estimated meteorological data for numerous locations in the French Alps during the last ten years. Comparisons with observed snow characteristics (e.g., depth and stratigraphy) have proved the potential of the method.

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