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 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 Specifics of boglands freezing in the north and northwest of the European part of Russia under climate change

2019 ◽  
Vol 59 (2) ◽  
pp. 233-244
Author(s):  
V. I. Batuev ◽  
I. L. Kalyuzhny
Keyword(s):  
Ambient Temperature ◽  
Snow Cover ◽  
Spatial And Temporal Variability ◽  
North West ◽  
The North ◽  
Climatic Period ◽  
European Part Of Russia ◽  
Freezing Depth ◽  
Main Factors ◽  
Cover Thickness

Long-term complex observations covering the period of 1949–2018 made possible to determine the average annual characteristics of the depth of freezing of wetlands in the North and Northwest of the European territory of Russia together with main factors of its formation, and spatial and temporal variability. The main factors that determine the depth of freezing of wetlands are ambient temperature, snow cover thickness, and a degree of watering of the micro landscape (water reserves of the micro landscape). At the initial stage of freezing, the major factor is the ambient temperature, when intensity of the freezing reaches 0.5–0.8 cm/day. As snow falls, the freezing rate becomes smaller, and when the snow cover thickness reaches 25–30 cm the depth amounts to 0.2–0.3 cm/day and smaller. It was found that the spatial variability of the freezing depth decreases from large values of the coefficient of variation (0.3–0.4) at the depth of 20–30 cm to less than 0.1 when the depth exceeds 60 cm. The largest values of the depth are recorded in the North of the Kola Peninsula, where sometimes they reach from 84 to 97 cm with the average values of 48–66. In large hummocky bogs, when the seasonal freezing comes down to 63–65 cm it links with the permafrost layer. On average, swamps of these bogs freeze down to a depth of 68 cm. The average climatic depth of freezing of oligotrophic bogs of the NorthWest is 21–24 cm; in some years, freezing of them reaches 32–40 cm. It has been shown that the relative warming of the climate resulted in decreasing in the depth of freezing of wetlands in the North and North-West of the European territory of Russia. Relative to the previous climatic period, the depth of frost penetration in the northern Ilasskoye bog decreased by 32%, and in north-western Lammin-Suo bog – by 31%.

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 Long-term variability of aerosol optical thickness in Eastern Europe over 2001–2014 according to the measurements at the Moscow MSU MO AERONET site with additional cloud and NO<sub>2</sub> correction

2015 ◽  
Vol 8 (7) ◽  
pp. 7843-7878
Author(s):  
N. Y. Chubarova ◽  
A. A. Poliukhov ◽  
I. D. Gorlova
Keyword(s):  
Optical Thickness ◽  
Aerosol Optical Thickness ◽  
Quality Data ◽  
Emission Rates ◽  
State University ◽  
Data Control ◽  
Uv Irradiance ◽  
Meteorological Observatory ◽  
Moscow State University

Abstract. The aerosol properties of the atmosphere were obtained within the framework of the AERONET program at the Moscow State University Meteorological Observatory (Moscow MSU MO) over 2001–2014 period. The quality data control has revealed the necessity of their additional cloud and NO2 correction. The application of cloud correction according to hourly visual cloud observations provides a decrease in average aerosol optical thickness (AOT) at 500 nm of up to 0.03 compared with the standard dataset. We also show that the additional NO2 correction of the AERONET data is needed in large megalopolis, like Moscow, with 12 million residents and the NOx emission rates of about 100 kt yr−1. According to the developed method we estimated monthly mean NO2 content, which provides an additional decrease of 0.01 for AOT at 340 nm, and of about 0.015 – for AOT at 380 and 440 nm. The ratios of NO2 optical thickness to AOT at 380 and 440 nm are about 5–6 % in summer and reach 15–20 % in winter when both factors have similar effects on UV irradiance. Seasonal cycle of AOT at 500 nm is characterized by a noticeable summer and spring maxima, and minimum in winter conditions, changing from 0.08 in December and January up to 0.3 in August. The application of the additional cloud correction removes a local AOT maximum in February, and lowered the December artificial high AOT values. The pronounced negative AOT trends of about −1–5 % yr−1 have been obtained for most months, which could be attributed to the negative trends in emissions (E) of different aerosol precursors of about 116 Gg yr−2 in ESOx, 78 Gg yr−2 in ENMVOC, and 272 Gg yr−2 in ECO over European territory of Russia. No influence of natural factors on temporal AOT variations has been revealed.

scholarly journals THE USE OF THE ISOTOPIC METHOD IN THE ASSESSMENT OF THE URBANIZATION OF ATMOSPHERIC PRECIPITATION IN MOSCOW

2019 ◽  
Vol 96 (8) ◽  
pp. 737-743
Author(s):  
Yu. N. Chizhova ◽  
I. D. Eremina ◽  
N. A. Budantseva ◽  
G. V. Surkova ◽  
Yu. K Vasilchuk
Keyword(s):  
Atmospheric Precipitation ◽  
Climatic Conditions ◽  
State University ◽  
Air Masses ◽  
Isotopic Method ◽  
Meteorological Observatory ◽  
Anions And Cations ◽  
Accumulation Of Pollutants ◽  
The Individual ◽  
Moscow State University

The study was carried out on the basis of all the individual samples (101 cases) of precipitation for 2014, sampled at the Meteorological Observatory of Moscow State University. The concentrations of the main anions and cations, the total mineralization and δ18O values were determined. 12 cases of relatively high mineralization of precipitation were recorded. Average weighted mineralization values ranged from 12.0 to 67.7 mg/L, specific values of mineralization varied from 3.2 to 229.0 mg/L. Chlorine prevails among anions, calcium prevails among cations. The used isotope data analysis and backward trajectories of air masses showed the hydro-chemical composition of precipitation in Moscow not to be linked to the origin of air masses. This indicates to the predominantly urban origin of pollutants in precipitation. In general, in 2014 precipitation were significantly more mineralized than in previous years of observations, due to the climatic conditions of a particular year - small amount of precipitation and number of days with precipitation. This has led to the accumulation of pollutants in the atmosphere and the poor washout of pollutants.

scholarly journals Spatio-temporal heterogeneity of the snow cover from data of the penetrometer SnowMicroPen

2018 ◽  
Vol 58 (4) ◽  
pp. 473-485
Author(s):  
A. Y. Komarov ◽  
Y. G. Seliverstov ◽  
P. B. Grebennikov ◽  
S. A. Sokratov
Keyword(s):  
Snow Cover ◽  
Temporal Variability ◽  
Climatic Conditions ◽  
Spatial And Temporal Variability ◽  
State University ◽  
Direct Data ◽  
Homogeneous Area ◽  
Spatio Temporal ◽  
University City ◽  
Moscow State University

Te paper presents the results of studies aimed at investigation of the spatial and temporal variability of snow coverstructure on the basis of strength values and its variations obtained by means of the high-resolution penetrometer SnowMicroPen. Te possibilities of fast and independent from the observer identifcation of layers (including identifcation of weakened, potentially avalanche-dangerous layers) were estimated under the climatic conditions of Moscow and the Khibiny mountains. Horizontal areas with homogeneous underlying surface and vegetation were selected for the stratigraphic studies that made it possible to avoid a possible influence of slope relief and exposure from the obtained data on the spatial and temporal variability of the snow depth structure. Te analysis of the information obtained in winter seasons 2014/15 and 2016/17 allowed constructing detailed schemes of the snow cover evolution at the Moscow site as well as assessing the inter-annual and intra-seasonal variability of its structure. Afer the SnowMicroPen data were recorded in the course of the feld works carried out in winter 2015/16 on the Khibiny educational and scientifc base of the Lomonosov Moscow State University (city of Kirovsk), the 10-meter trench on the same profle was described in details, and direct data on the snow cover structure were obtained. Te strength values resulted from the above studies characterize the layers composed of crystals of various shapes and sizes, and they are considered as the frst step to methodology of operational defnition of the spatially-inhomogeneous stratigraphy and stability of snowpack without snowpit observations. Te data analysis showed high spatial and temporal variability of the structure and properties of snow cover even at a homogeneous area, usually described by a single snowpit.

scholarly journals Dynamics of snow cover characteristics exerting influence on stability of the Svalbard permafrost

2016 ◽  
Vol 56 (2) ◽  
pp. 189-198 ◽  
Author(s):  
N. I. Osokin ◽  
A. V. Sosnovsky
Keyword(s):  
Snow Cover ◽  
Thermal State ◽  
Cold Season ◽  
Rainfall Amount ◽  
Meteorological Station ◽  
Climate Variations ◽  
Time Duration ◽  
Ground Freezing ◽  
Small Change ◽  
Cover Thickness

Climate variations result in changes of the snow cover characteristics which have a certain influence upon thermal state and stability of permafrost. Analysis of data of meteorological station Barentsburg (Svalbard) and our own observations has revealed small change in the snow cover thickness for the period 1984–2015. At the same time, duration of the snow cover presence has shortened by 8%. In recent years, more than 60% of the snow cover thickness was formed during the early third of the cold season which adversely affects a rate of the ground freezing. Durations of thaws increased from 12 to 22 days, and the rainfall amount decreased during the cold period from 60 to 120 mm. The largest increase in the thaw duration (by a factor of 7) and decrease of the rainfall amount (by a factor of 8) fall on January and February. Summing up of the thaw duration and the rainfall amount for the 5‑year periods demonstrated significant growth of both. It should be noted also that, according to data of the Barentsburg station and our ones, in a few last years, these parameters reached anomalously high values. Appearance of anomalous values of the snow cover thickness as well as of the dates of its onset became more frequent. For the last decade, recurrence of anomalous values of the snow cover thickness increased: one event for 2.4 years before 2000, and one occurrence of anomalous thickness for 1.4 years since 2001. The later onset of snow cover resulted in shortening of duration of its presence. Occurrence of anomalous duration of the snow cover presence was observed once for 4.3 years before 2001, and once for 3.3 years after 2000.

Sign in / Sign up

Export Citation Format

Share Document