Pub Date : 2019-03-20DOI: 10.15356/2076-6734-2019-1-39-48
A. Boronina, S. Popov, G. Pryakhina
Broknes Peninsula (the area of the Progress station, Larsemann Hills, Princess Elisabeth Land, East Antarctica) is characterized by the presence of well developed hydrographic network consisting of reservoirs located not only in the bedrock, but also inside the glacier thickness and on its surface. As a rule, most of them are dammed by natural snowice weirs, which are often destroyed during the Antarctic summer. As a result of this process, glacial water outburst may occur. In the course of the summer season of the 63‑th Russian Antarctic Expedition (RAE) intensive hydrological field observations were carried out for identification and comprehensive investigation of potentially outburstprone reservoirs located in close proximity to Russian and foreign stations and field bases (area of the Progress station and the field base Law-Racovita). The works included: the organization of temporary pile and depth-stick water gauge stations, mapping positions of the shoreline of lakes (reservoirs), bathymetric surveys of them, as well as field hydro-chemical express analyses. Based on the results of the level measurement, it was found that most of the lakes of the oasis are characterized by a sharp drop in the height of the water surface level associated with the breakthroughs. In particular, the authors witnessed the breakthrough of the Discussion Lake, which occurred on January 22, 2018. This resulted in decrease of the water level by 0.95 m. Based on the data of the bathymetric surveys, the morphometric (hydrometric) characteristics of the lakes were calculated and detailed grids (regular net of rectangular matrices, in the nodes of which some effective values of the mapped values are located) were formed for the following numerical modeling of hypothetical and real breakthroughs of water bodies and construction of estimated hydrographs.
布罗克尼斯半岛(Progress station, Larsemann Hills, Princess Elisabeth Land，东南极洲)的特点是存在发达的水文网络，包括不仅位于基岩，而且位于冰川厚度内部及其表面的水库。通常，它们中的大多数都是由天然的雪堰筑成的，这些雪堰经常在南极的夏季被破坏。由于这一过程，可能会发生冰川溃决。在第63次俄罗斯南极考察队(RAE)的夏季期间，进行了密集的野外水文观测，以确定和全面调查靠近俄罗斯和外国站和野外基地(Progress站和Law-Racovita野外基地地区)的潜在突发性水库。工作内容包括:临时桩、深杆水位测量站的组织，湖(库)岸线位置的测绘，湖(库)岸线的水深测量，以及现场水化学快速分析。根据水位测量结果发现，绿洲大部分湖泊的水面高度随突围而急剧下降。特别是在2018年1月22日，作者见证了讨论湖的突破。这导致水位下降了0.95米。根据测深数据，计算湖泊的形态(水文)特征，形成详细网格(矩形矩阵的规则网，映射值的有效值在其节点上)，用于后续水体假设突破和实际突破的数值模拟和估算水文线的构建。
{"title":"Hydrological characteristics of lakes in the eastern part of the Broknes Peninsula, Larsemann Hills, East Antarctica","authors":"A. Boronina, S. Popov, G. Pryakhina","doi":"10.15356/2076-6734-2019-1-39-48","DOIUrl":"https://doi.org/10.15356/2076-6734-2019-1-39-48","url":null,"abstract":"Broknes Peninsula (the area of the Progress station, Larsemann Hills, Princess Elisabeth Land, East Antarctica) is characterized by the presence of well developed hydrographic network consisting of reservoirs located not only in the bedrock, but also inside the glacier thickness and on its surface. As a rule, most of them are dammed by natural snowice weirs, which are often destroyed during the Antarctic summer. As a result of this process, glacial water outburst may occur. In the course of the summer season of the 63‑th Russian Antarctic Expedition (RAE) intensive hydrological field observations were carried out for identification and comprehensive investigation of potentially outburstprone reservoirs located in close proximity to Russian and foreign stations and field bases (area of the Progress station and the field base Law-Racovita). The works included: the organization of temporary pile and depth-stick water gauge stations, mapping positions of the shoreline of lakes (reservoirs), bathymetric surveys of them, as well as field hydro-chemical express analyses. Based on the results of the level measurement, it was found that most of the lakes of the oasis are characterized by a sharp drop in the height of the water surface level associated with the breakthroughs. In particular, the authors witnessed the breakthrough of the Discussion Lake, which occurred on January 22, 2018. This resulted in decrease of the water level by 0.95 m. Based on the data of the bathymetric surveys, the morphometric (hydrometric) characteristics of the lakes were calculated and detailed grids (regular net of rectangular matrices, in the nodes of which some effective values of the mapped values are located) were formed for the following numerical modeling of hypothetical and real breakthroughs of water bodies and construction of estimated hydrographs.","PeriodicalId":43880,"journal":{"name":"Led i Sneg-Ice and Snow","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2019-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66931003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-20DOI: 10.15356/2076-6734-2019-1-112-122
S. Krasheninnikova, M. Krasheninnikova
Based on the spectral analysis of a number of estimates of the ice extent of the Barents Sea, obtained from instrumental observational data for 1900–2014, and for the selected CMIP5 project models (MPI-ESM-LR, MPI-ESMMR and GFDL-CM3) for 1900–2005, a typical period of ~60‑year inter-annual variability associated with the Atlantic multidecadal oscillation (AMO) in conditions of a general significant decrease in the ice extent of the Barents Sea, which, according to observations and model calculations, was 20 and 15%, respectively, which confirms global warming. The maximum contribution to the total dispersion of temperature, ice cover of the Barents Sea, AMO, introduces variability with periods of more than 20 years and trends that are 47, 20, 51% and 33, 57, 30%, respectively. On the basis of the cross correlation analysis, significant links have been established between the ice extent of the Barents Sea, AMO, and North Atlantic Oscillation (NAO) for the period 1900–2014. A significant negative connection (R = −0.8) of ice cover and Atlantic multi-decadal oscillations was revealed at periods of more than 20 years with a shift of 1–2 years; NAO and ice cover (R = −0.6) with a shift of 1–2 years for periods of 10–20 years; AMO and NAO (R = −0.4 ÷ −0.5) with a 3‑year shift with AMO leading at 3–4, 6–8 and more than 20 years. The periods of the ice cover growth are specified: 1950–1980 and the reduction of the ice cover: the 1920–1950 and the 1980–2010 in the Barents Sea. Intensification of the transfer of warm waters from the North Atlantic to the Arctic basin, under the atmospheric influence caused by the NAO, accompanied by the growth of AMO leads to an increase in temperature, salinity and a decrease of ice cover in the Barents Sea. During periods of ice cover growth, opposite tendencies appear. The decrease in the ice cover area of the entire Northern Hemisphere by 1.5 × 106 km2 since the mid-1980s. to the beginning of the 2010, identified in the present work on NOAA satellite data, confirms the results obtained on the change in ice extent in the Barents Sea.
{"title":"Causes and features of long-term variability of the ice extent in the Barents Sea","authors":"S. Krasheninnikova, M. Krasheninnikova","doi":"10.15356/2076-6734-2019-1-112-122","DOIUrl":"https://doi.org/10.15356/2076-6734-2019-1-112-122","url":null,"abstract":"Based on the spectral analysis of a number of estimates of the ice extent of the Barents Sea, obtained from instrumental observational data for 1900–2014, and for the selected CMIP5 project models (MPI-ESM-LR, MPI-ESMMR and GFDL-CM3) for 1900–2005, a typical period of ~60‑year inter-annual variability associated with the Atlantic multidecadal oscillation (AMO) in conditions of a general significant decrease in the ice extent of the Barents Sea, which, according to observations and model calculations, was 20 and 15%, respectively, which confirms global warming. The maximum contribution to the total dispersion of temperature, ice cover of the Barents Sea, AMO, introduces variability with periods of more than 20 years and trends that are 47, 20, 51% and 33, 57, 30%, respectively. On the basis of the cross correlation analysis, significant links have been established between the ice extent of the Barents Sea, AMO, and North Atlantic Oscillation (NAO) for the period 1900–2014. A significant negative connection (R = −0.8) of ice cover and Atlantic multi-decadal oscillations was revealed at periods of more than 20 years with a shift of 1–2 years; NAO and ice cover (R = −0.6) with a shift of 1–2 years for periods of 10–20 years; AMO and NAO (R = −0.4 ÷ −0.5) with a 3‑year shift with AMO leading at 3–4, 6–8 and more than 20 years. The periods of the ice cover growth are specified: 1950–1980 and the reduction of the ice cover: the 1920–1950 and the 1980–2010 in the Barents Sea. Intensification of the transfer of warm waters from the North Atlantic to the Arctic basin, under the atmospheric influence caused by the NAO, accompanied by the growth of AMO leads to an increase in temperature, salinity and a decrease of ice cover in the Barents Sea. During periods of ice cover growth, opposite tendencies appear. The decrease in the ice cover area of the entire Northern Hemisphere by 1.5 × 106 km2 since the mid-1980s. to the beginning of the 2010, identified in the present work on NOAA satellite data, confirms the results obtained on the change in ice extent in the Barents Sea.","PeriodicalId":43880,"journal":{"name":"Led i Sneg-Ice and Snow","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2019-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66930920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-20DOI: 10.15356/2076-6734-2019-1-67-80
S. Pozdniakov, S. O. Grinevskyi, E. Dedulina, E. S. Koreko
The relationship between the results of calculations of the dynamics of the temperature regime of the in freezing and thawing soil profile with the heating effect of the snow cover is considered. To analyze this connection, two coupled models are used: the model of formation and degradation of snow cover in winter and the model of heat transfer and soil moisture transport in underlying vadoze zone profile. Parametrization of the influence of the snow cover, which at each calculated moment of time has the current average density and depth, on the dynamics of the temperatures of the soil profile is due to the use of its specific thermal resistance, which depends on its current depth and the thermal conductivity coefficient. The coefficient of thermal conductivity of the snow cover is related with its density using six different published empirical relationships. Modeling of heat transfer in freezing and thawing soil is carried out on the example of the field site for monitoring the thermal regime located on the territory of the Zvenigorod Biological Station of Moscow State University. It is shown that the well-known relationships give similar curves for the dynamics of the depth of seasonal freezing, including the degradation of the seasonal freezing layer in the spring period, with the same dynamics of the snow cover. However, the maximum penetration depth of the zero isotherm differs significantly for different snow conductivity-snow density relationships. The tested six relationships were divided into three groups. Minimal freezing is provided by the Sturm model and the effective medium model. The average and rather poorly differentiating freezing from each other is given by the Pavlov, Osokin et al. and Jordan relationships. The greatest value of the freezing depth is obtained with using Pavlov’s relationship with a temperature correction.
{"title":"Sensitivity of the results of modeling of seasonal ground freezing to selection of parameterization of the snow cover thermal conductivity","authors":"S. Pozdniakov, S. O. Grinevskyi, E. Dedulina, E. S. Koreko","doi":"10.15356/2076-6734-2019-1-67-80","DOIUrl":"https://doi.org/10.15356/2076-6734-2019-1-67-80","url":null,"abstract":"The relationship between the results of calculations of the dynamics of the temperature regime of the in freezing and thawing soil profile with the heating effect of the snow cover is considered. To analyze this connection, two coupled models are used: the model of formation and degradation of snow cover in winter and the model of heat transfer and soil moisture transport in underlying vadoze zone profile. Parametrization of the influence of the snow cover, which at each calculated moment of time has the current average density and depth, on the dynamics of the temperatures of the soil profile is due to the use of its specific thermal resistance, which depends on its current depth and the thermal conductivity coefficient. The coefficient of thermal conductivity of the snow cover is related with its density using six different published empirical relationships. Modeling of heat transfer in freezing and thawing soil is carried out on the example of the field site for monitoring the thermal regime located on the territory of the Zvenigorod Biological Station of Moscow State University. It is shown that the well-known relationships give similar curves for the dynamics of the depth of seasonal freezing, including the degradation of the seasonal freezing layer in the spring period, with the same dynamics of the snow cover. However, the maximum penetration depth of the zero isotherm differs significantly for different snow conductivity-snow density relationships. The tested six relationships were divided into three groups. Minimal freezing is provided by the Sturm model and the effective medium model. The average and rather poorly differentiating freezing from each other is given by the Pavlov, Osokin et al. and Jordan relationships. The greatest value of the freezing depth is obtained with using Pavlov’s relationship with a temperature correction. ","PeriodicalId":43880,"journal":{"name":"Led i Sneg-Ice and Snow","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2019-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66930964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-20DOI: 10.15356/2076-6734-2019-1-93-102
N. Budantseva, Y. Vasil'chuk
The object of research is syncryogenic Holocene strata on the coast of the Onemen Bay, 2 km from the town of Anadyr. In July 2017, the outcrop of the first marine terrace uncovered by strong storms was examined. The stratigraphy of the outcrop was represented mainly by sandy loam (5–7 m thick) covered by peat (1–1.5 m) and underlain by sand. Numerous ice wedges were opened in the upper part of this outcrop. Along with that another outcropping of transect of a lakemarsh basin represented by a peat bog of 2–2.5 m thick underlain by sandy loam was also investigated. Ice wedges occur below the polygonal trenches. The present-day narrow ice wedges were found in the upper part of the peat bog. Two representative fragments of both the above outcrops were thoroughly examined. Radiocarbon dating had shown that accumulation of peat on surface of the first marine terrace started in early Holocene (about 8 ka BP). Accumulation of peatland within the lake-marsh basin was also dated to the beginning of the Holocene (about 9 ka BP). In the middle of the Holocene, it was most likely interrupted as a result of thermokarst processes and bogging of the surface. Formation of peatlands in Chukotka during the Holocene is known to be accompanied by active growth of the ice wedges inside them, so the age of the wedges studied by us was estimated as the beginning of the Holocene. The analysis of stable oxygen and hydrogen isotopes in the Holocene and the modern ice wedges had allowed establishing mainly the atmospheric type of moisture feeding of the wedges (due to melted snow) and lack of noticeable isotope fractionation during the ice formation. It has been found that δ18О and δ2Н values in the Holocene ice wedges were lower than in the modern wedges and snow by an average 2–3 and 7–12 ‰, respectively. Paleotemperature reconstructions performed on the basis of isotopeoxygen data showed that the air temperature of the coldest winter month in the first half of the Holocene in the Onemen Bay area was lower than the present-day ones by an average 2–3 °C, which is in a good agreement with the trend of rising winter temperatures throughout the Chukotka Peninsula, as well as in other areas of Eastern Siberia and Alaska.
{"title":"Winter air temperature in Holocene reconstructed from the ice wedges stable water isotopes near Anadyr town","authors":"N. Budantseva, Y. Vasil'chuk","doi":"10.15356/2076-6734-2019-1-93-102","DOIUrl":"https://doi.org/10.15356/2076-6734-2019-1-93-102","url":null,"abstract":"The object of research is syncryogenic Holocene strata on the coast of the Onemen Bay, 2 km from the town of Anadyr. In July 2017, the outcrop of the first marine terrace uncovered by strong storms was examined. The stratigraphy of the outcrop was represented mainly by sandy loam (5–7 m thick) covered by peat (1–1.5 m) and underlain by sand. Numerous ice wedges were opened in the upper part of this outcrop. Along with that another outcropping of transect of a lakemarsh basin represented by a peat bog of 2–2.5 m thick underlain by sandy loam was also investigated. Ice wedges occur below the polygonal trenches. The present-day narrow ice wedges were found in the upper part of the peat bog. Two representative fragments of both the above outcrops were thoroughly examined. Radiocarbon dating had shown that accumulation of peat on surface of the first marine terrace started in early Holocene (about 8 ka BP). Accumulation of peatland within the lake-marsh basin was also dated to the beginning of the Holocene (about 9 ka BP). In the middle of the Holocene, it was most likely interrupted as a result of thermokarst processes and bogging of the surface. Formation of peatlands in Chukotka during the Holocene is known to be accompanied by active growth of the ice wedges inside them, so the age of the wedges studied by us was estimated as the beginning of the Holocene. The analysis of stable oxygen and hydrogen isotopes in the Holocene and the modern ice wedges had allowed establishing mainly the atmospheric type of moisture feeding of the wedges (due to melted snow) and lack of noticeable isotope fractionation during the ice formation. It has been found that δ18О and δ2Н values in the Holocene ice wedges were lower than in the modern wedges and snow by an average 2–3 and 7–12 ‰, respectively. Paleotemperature reconstructions performed on the basis of isotopeoxygen data showed that the air temperature of the coldest winter month in the first half of the Holocene in the Onemen Bay area was lower than the present-day ones by an average 2–3 °C, which is in a good agreement with the trend of rising winter temperatures throughout the Chukotka Peninsula, as well as in other areas of Eastern Siberia and Alaska. ","PeriodicalId":43880,"journal":{"name":"Led i Sneg-Ice and Snow","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2019-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77901598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-20DOI: 10.15356/2076-6734-2019-1-135-144
M. Ananicheva, G. Pakin, Y. Kononov
Three glaciers and other small glacial formations, which are not mentioned in the USSR Catalog of glaciers as well as in any published article, were found in the area of the Verkhneangarsky (upper Angara) Range on satellite images. Earlier, researchers from the Institute of Geography of Siberian Branch of RAS described a group of glaciers on the Baikal Mountains and the Barguzin Range, which together with the above group of the Verkhneangarsky Range are related to the Baikal basin by the climate conditions. Ogdynda-Maskit Glacier has been described on the spot in 2017, while other glaciers and snow patches are to be investigated in situ in 2018. Together with the above Baikal and Barguzin glaciers, new data allow identification of the Baikal Glacial system. The article presents analysis of climate changes in the region. Trends in mean annual temperature range from 1 to 4 °C/50 years, while the same of summer temperatures change from 1 to 3 °C/50 years, but without any evident spatial distribution between them. Another situation takes place in the spatial distribution of precipitation: trends in total precipitation decrease towards the Baikal Lake, while precipitation of the cold period, on the contrary, slightly increases towards the Lake, but with rather small trend – 10–40 mm per 50 years. The last fact confirms the influence of the Baikal basin on the alimentation of glaciers and snow patches on the Verkhneangarsky Range. Currently, glaciers of the Verkhneangarsky Range undergo a slow regression.
卫星图像显示，在Verkhneangarsky(上安加拉)山脉地区发现了三个冰川和其他小型冰川构造，这些冰川在苏联冰川目录和任何已发表的文章中都没有提到。此前，俄罗斯科学院西伯利亚分院地理研究所的研究人员描述了贝加尔湖山脉和巴尔古津山脉上的一组冰川，这些冰川与Verkhneangarsky山脉的上述冰川组一起，通过气候条件与贝加尔湖盆地相关。Ogdynda-Maskit冰川已于2017年在现场进行了描述，而其他冰川和积雪将于2018年在现场进行调查。与上述贝加尔湖和巴尔古津冰川一起，新的数据可以确定贝加尔湖冰川系统。文章对该地区的气候变化进行了分析。年平均气温变化趋势在1 ~ 4°C/50 a之间，夏季气温变化趋势在1 ~ 3°C/50 a之间，但两者之间没有明显的空间分布。降水空间分布的另一种情况是，总降水向贝加尔湖方向呈减少趋势，而寒期降水向贝加尔湖方向略有增加，但趋势较小，为10-40 mm / 50年。最后一个事实证实了贝加尔湖盆地对Verkhneangarsky山脉冰川和积雪营养的影响。目前，Verkhneangarsky山脉的冰川正在缓慢消退。
{"title":"Baikal glacier system, new findings","authors":"M. Ananicheva, G. Pakin, Y. Kononov","doi":"10.15356/2076-6734-2019-1-135-144","DOIUrl":"https://doi.org/10.15356/2076-6734-2019-1-135-144","url":null,"abstract":"Three glaciers and other small glacial formations, which are not mentioned in the USSR Catalog of glaciers as well as in any published article, were found in the area of the Verkhneangarsky (upper Angara) Range on satellite images. Earlier, researchers from the Institute of Geography of Siberian Branch of RAS described a group of glaciers on the Baikal Mountains and the Barguzin Range, which together with the above group of the Verkhneangarsky Range are related to the Baikal basin by the climate conditions. Ogdynda-Maskit Glacier has been described on the spot in 2017, while other glaciers and snow patches are to be investigated in situ in 2018. Together with the above Baikal and Barguzin glaciers, new data allow identification of the Baikal Glacial system. The article presents analysis of climate changes in the region. Trends in mean annual temperature range from 1 to 4 °C/50 years, while the same of summer temperatures change from 1 to 3 °C/50 years, but without any evident spatial distribution between them. Another situation takes place in the spatial distribution of precipitation: trends in total precipitation decrease towards the Baikal Lake, while precipitation of the cold period, on the contrary, slightly increases towards the Lake, but with rather small trend – 10–40 mm per 50 years. The last fact confirms the influence of the Baikal basin on the alimentation of glaciers and snow patches on the Verkhneangarsky Range. Currently, glaciers of the Verkhneangarsky Range undergo a slow regression. ","PeriodicalId":43880,"journal":{"name":"Led i Sneg-Ice and Snow","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2019-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74093997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-20DOI: 10.15356/2076-6734-2019-1-81-92
L. Neradovsky
The previously unknown dependence between the volume ice content of frozen dispersed soils and their radiophysical properties (the speed of propagation and specific attenuation of the amplitude of electromagnetic waves) was studied in the layer of annual heat flows of Central Yakutia. The correlation between these characteristics determined in the laboratory and the method of discrete georadiolocation is established. The peculiarity of the connection is the sharp decline in the sensitivity of the propagation speed and the specific attenuation of electromagnetic waves in frozen dispersed soils with high volume ice content (more than 60%). In general, the specific attenuation of electromagnetic waves is more responsive to the change in the volume of ice content of frozen dispersed soils and, thus, it is more preferable to solve the problem of quantitative evaluation of this characteristic. The proposed method of reusable measurements of signals of georadiolocation with changing position and azimuth of antennas of georadars in the vicinity of the network points of geological and geophysical observations allows to estimate the average values of the propagation speed and specific attenuation of electromagnetic waves with an error of not more than 10%. Due to this, according to the equations of logistic functions it is possible to calculate the average values of volume ice content with an error of 7–11%. With this error, the picture of the probability distribution according to the georadiolocation values of the volume ice content in the averages is completely identical to the laboratory data. On this basis, the found regression equations are recommended to be used for the calculation of the speed of propagation and specific attenuation of electromagnetic waves of background or average values of the volume ice content of frozen dispersed soils of the annual heat transfer layer in any part of the ice complex of the Central Yakut lowland.
{"title":"The GPR-based estimation of the volumetric ice content of dispersed ground in the Central Yakut lowland","authors":"L. Neradovsky","doi":"10.15356/2076-6734-2019-1-81-92","DOIUrl":"https://doi.org/10.15356/2076-6734-2019-1-81-92","url":null,"abstract":"The previously unknown dependence between the volume ice content of frozen dispersed soils and their radiophysical properties (the speed of propagation and specific attenuation of the amplitude of electromagnetic waves) was studied in the layer of annual heat flows of Central Yakutia. The correlation between these characteristics determined in the laboratory and the method of discrete georadiolocation is established. The peculiarity of the connection is the sharp decline in the sensitivity of the propagation speed and the specific attenuation of electromagnetic waves in frozen dispersed soils with high volume ice content (more than 60%). In general, the specific attenuation of electromagnetic waves is more responsive to the change in the volume of ice content of frozen dispersed soils and, thus, it is more preferable to solve the problem of quantitative evaluation of this characteristic. The proposed method of reusable measurements of signals of georadiolocation with changing position and azimuth of antennas of georadars in the vicinity of the network points of geological and geophysical observations allows to estimate the average values of the propagation speed and specific attenuation of electromagnetic waves with an error of not more than 10%. Due to this, according to the equations of logistic functions it is possible to calculate the average values of volume ice content with an error of 7–11%. With this error, the picture of the probability distribution according to the georadiolocation values of the volume ice content in the averages is completely identical to the laboratory data. On this basis, the found regression equations are recommended to be used for the calculation of the speed of propagation and specific attenuation of electromagnetic waves of background or average values of the volume ice content of frozen dispersed soils of the annual heat transfer layer in any part of the ice complex of the Central Yakut lowland. ","PeriodicalId":43880,"journal":{"name":"Led i Sneg-Ice and Snow","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2019-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84994568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-20DOI: 10.15356/2076-6734-2019-1-5-22
O. Rototaeva, G. Nosenko, A. M. Kerimov, S. Kutuzov, I. Lavrentiev, S. Nikitin, A. Kerimov, L. Tarasova
Long-term series of observations on the glacier of the southern slope of Elbrus manifest the change of two climatic periods in the highlands of the Caucasus. During the first one, relatively cold and snowy period of 1982–1997 with a small positive mass balance, the Garabashi Glacier accumulated a layer of 0.8 m.e. The second period (1998–2017) is characterized by rising summer air temperatures and increasing precipitation in the first decade, and catastrophic melting in 2010–2017. The mass balance of the glacier averaged −0.63 m w.e. yr−1, and in some years it reached −1.00 ÷ −1.50 m w.e. yr−1. In the last ten years, frequency of vast anticyclones covering the southern part of the European part of Russia and the North Caucasus increased. Summer temperatures in the Elbrus region rose to almost the level of the 1950s that was the hottest decade of the XX century. Duration of the summer season on the glaciers increased. Active melting resulted in elevation of the equilibrium line of the Garabashy Glacier by 200 m. In the main part of the glacier alimentation area, i.e. at heights of 3800–4000 m, the large parts of the firn area had disappeared, but open ice of the ablation zone had appeared. The former areas of the "warm" firn zone, where up to 35% of melt water retained within the 20‑meter firn thickness, were replaced by the firn-ice zone, and the ice discharge increased. The glacier alimentation is decreased, and its tongue retreats with increasing velocity. Rocks and entire lava ridges release from ice at different levels of the glacier. The inter-annual variations of the glacier mass balance are controlled by intensity of ablation. In the second period, the correlation coefficient of these values reached 0.97 compared to 0.82 in the first one. In total over 36 years of observations, reduction of the glacier mass during the second period resulted in loss of volume (0.05 km3 or 14%), area (0.51 km2 or 11.4%), and of ice layer (11.4 m).
{"title":"Changes of the mass balance of the Garabashy Glacier, Mount Elbrus, at the turn of 20th and 21st centuries","authors":"O. Rototaeva, G. Nosenko, A. M. Kerimov, S. Kutuzov, I. Lavrentiev, S. Nikitin, A. Kerimov, L. Tarasova","doi":"10.15356/2076-6734-2019-1-5-22","DOIUrl":"https://doi.org/10.15356/2076-6734-2019-1-5-22","url":null,"abstract":"Long-term series of observations on the glacier of the southern slope of Elbrus manifest the change of two climatic periods in the highlands of the Caucasus. During the first one, relatively cold and snowy period of 1982–1997 with a small positive mass balance, the Garabashi Glacier accumulated a layer of 0.8 m.e. The second period (1998–2017) is characterized by rising summer air temperatures and increasing precipitation in the first decade, and catastrophic melting in 2010–2017. The mass balance of the glacier averaged −0.63 m w.e. yr−1, and in some years it reached −1.00 ÷ −1.50 m w.e. yr−1. In the last ten years, frequency of vast anticyclones covering the southern part of the European part of Russia and the North Caucasus increased. Summer temperatures in the Elbrus region rose to almost the level of the 1950s that was the hottest decade of the XX century. Duration of the summer season on the glaciers increased. Active melting resulted in elevation of the equilibrium line of the Garabashy Glacier by 200 m. In the main part of the glacier alimentation area, i.e. at heights of 3800–4000 m, the large parts of the firn area had disappeared, but open ice of the ablation zone had appeared. The former areas of the \"warm\" firn zone, where up to 35% of melt water retained within the 20‑meter firn thickness, were replaced by the firn-ice zone, and the ice discharge increased. The glacier alimentation is decreased, and its tongue retreats with increasing velocity. Rocks and entire lava ridges release from ice at different levels of the glacier. The inter-annual variations of the glacier mass balance are controlled by intensity of ablation. In the second period, the correlation coefficient of these values reached 0.97 compared to 0.82 in the first one. In total over 36 years of observations, reduction of the glacier mass during the second period resulted in loss of volume (0.05 km3 or 14%), area (0.51 km2 or 11.4%), and of ice layer (11.4 m).","PeriodicalId":43880,"journal":{"name":"Led i Sneg-Ice and Snow","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2019-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66931119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-20DOI: 10.15356/2076-6734-2019-1-23-38
I. Lavrentiev, A. Glazovsky, Y. Macheret, V. Matskovsky, A. Y. Muravyev
Data on thickness and area of 16 glaciers on the Nordenskiöld Land (Svalbard) were obtained in 1999 and 2010–2013. These data were used to determine volume of the glaciers and to establish statistical local relationship between the volume V and the area A (V–A scaling) in the form of the power function V = cAγ, and then to calculate the total ice volume of all 202 glaciers in this area and its changes during the period since 1936 to 2002–2008. The total area of 16 glaciers was 129.9±0.35 km2, 14 of which had areas from 0.2 to 8.1 km2. The two largest ones, the Fridtjof and the West Grenfjord, had the areas 17.5 and 47.3 km2, respectively, and thus occupied about 50% (64.8 km2) of the total area of 16 glaciers. These two glaciers account for 67% of the total measured volume (10,034 km3) of the 16 glaciers. A nonlinear least-squares method was used to estimate ice reserves in all 202 glaciers from data on the volume and area of 16 glaciers. The relation between volume V and area A of the glaciers (V–A scaling) was obtained as the ratio V = 0.03637A1,283 with 95%‑th confidence intervals of the coefficients с and γ, (0.02303–0,4971) and (1.184–1.381), respectively. This made possible to calculate total volume of 202 glaciers as of 2002-2008 state using data from RGI v.6.0, and that prove to be equal to 32.89 (16.75–56.63) km3. To verify this estimation, we applied the bootstrapping method for chosen 43 glaciers and calculated the volume by means of sequential use of data for large and smaller glaciers. According to this estimate, the total volume of 202 glaciers amounted to 30.34 km3 with a 95% confidence interval of 15.42–44.27 km3, that turned out to be slightly smaller than the volume calculated by nonlinear least squares method basing on measurements on 16 glaciers. Despite the large error (on the average, from −49% to +84%) in estimating the total volume of 202 glaciers in the Nordenskiöld Land, the data obtained were used for assessment of relative changes in the total volume of glaciers in this area over different time intervals. During the period from 1936 to1990 (54 years), the total area of all glaciers reduced from 738.1 to 546.7 km2, and the total volume decreased from 49,205 to 34,857 km3. Similar results for the period 1990–2002–2008 (~15 years) are the total area changes from 546.7 to 507.9 km2 and their total volume - from 34.857 to 32.890 km3. The rate of decrease of the volume for the period 1936–1990 was equal to −0.266 km3/year, for the period 1990–2002–2008 – minus 0.131 km3/year, and as a whole for the studied period (since 1936 to 2002–2008) – minus 0.236 km3/year. The average mass balance in the first period was equal to −0.372 m w.e./year, in the second one −0.224 m w.e./year, and for the whole time −0.342 m w.e./year.
{"title":"Reserve of ice in glaciers on the Nordenskiöld Land, Spitsbergen, and their changes over the last decades","authors":"I. Lavrentiev, A. Glazovsky, Y. Macheret, V. Matskovsky, A. Y. Muravyev","doi":"10.15356/2076-6734-2019-1-23-38","DOIUrl":"https://doi.org/10.15356/2076-6734-2019-1-23-38","url":null,"abstract":"Data on thickness and area of 16 glaciers on the Nordenskiöld Land (Svalbard) were obtained in 1999 and 2010–2013. These data were used to determine volume of the glaciers and to establish statistical local relationship between the volume V and the area A (V–A scaling) in the form of the power function V = cAγ, and then to calculate the total ice volume of all 202 glaciers in this area and its changes during the period since 1936 to 2002–2008. The total area of 16 glaciers was 129.9±0.35 km2, 14 of which had areas from 0.2 to 8.1 km2. The two largest ones, the Fridtjof and the West Grenfjord, had the areas 17.5 and 47.3 km2, respectively, and thus occupied about 50% (64.8 km2) of the total area of 16 glaciers. These two glaciers account for 67% of the total measured volume (10,034 km3) of the 16 glaciers. A nonlinear least-squares method was used to estimate ice reserves in all 202 glaciers from data on the volume and area of 16 glaciers. The relation between volume V and area A of the glaciers (V–A scaling) was obtained as the ratio V = 0.03637A1,283 with 95%‑th confidence intervals of the coefficients с and γ, (0.02303–0,4971) and (1.184–1.381), respectively. This made possible to calculate total volume of 202 glaciers as of 2002-2008 state using data from RGI v.6.0, and that prove to be equal to 32.89 (16.75–56.63) km3. To verify this estimation, we applied the bootstrapping method for chosen 43 glaciers and calculated the volume by means of sequential use of data for large and smaller glaciers. According to this estimate, the total volume of 202 glaciers amounted to 30.34 km3 with a 95% confidence interval of 15.42–44.27 km3, that turned out to be slightly smaller than the volume calculated by nonlinear least squares method basing on measurements on 16 glaciers. Despite the large error (on the average, from −49% to +84%) in estimating the total volume of 202 glaciers in the Nordenskiöld Land, the data obtained were used for assessment of relative changes in the total volume of glaciers in this area over different time intervals. During the period from 1936 to1990 (54 years), the total area of all glaciers reduced from 738.1 to 546.7 km2, and the total volume decreased from 49,205 to 34,857 km3. Similar results for the period 1990–2002–2008 (~15 years) are the total area changes from 546.7 to 507.9 km2 and their total volume - from 34.857 to 32.890 km3. The rate of decrease of the volume for the period 1936–1990 was equal to −0.266 km3/year, for the period 1990–2002–2008 – minus 0.131 km3/year, and as a whole for the studied period (since 1936 to 2002–2008) – minus 0.236 km3/year. The average mass balance in the first period was equal to −0.372 m w.e./year, in the second one −0.224 m w.e./year, and for the whole time −0.342 m w.e./year. ","PeriodicalId":43880,"journal":{"name":"Led i Sneg-Ice and Snow","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2019-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72463551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-20DOI: 10.15356/2076-6734-2019-1-103-111
D. Zavyalov, T. Solomakha
Numerical experiments were carried out using the thermodynamic model with the aim to optimize choice of parameterization of the density of fresh snow, its albedo, and thermal conductivity coefficient in order to reproduce the seasonal evolution of ice thickness in the North-Eastern part of the Sea of Azov. The simulation results were compared with each other as well as with the observations obtained at the costal station of the Southern Scientific Center of the Russian Academy of Sciences in the Taganrog Bay. It is shown that small differences in the schemes of parameterization of physical and thermal properties of snow and ice cover may result in significant scatter in the simulation results. To assess the quality of the forecasting of the seasonal course of the ice thickness, the standard deviation of the calculated ice thickness from the average value for the period of measuring ice thickness, the standard deviation, the correlation coefficient, and the verification of the forecast were determined. Based on the analysis of these parameters, the optimal configuration of the snow layer parameters is proposed, which allows adequate reproducing of the seasonal thermal dynamics of the sea ice thickness. For the conditions of winter 2010/2011 the most close values of calculated ice thickness to results of the measurements in the North-Eastern part of the Taganrog Bay were obtained by determining the dependence of the density of fresh snow on the temperature in the near-surface layer of the atmosphere by the algorithm CLASS, albedo of the snow surface - by the scheme EHAM5, and the coefficient of thermal conductivity of snow – by the formulas of N.I. Osokin or M. Janson.
{"title":"Influence of new snow on growth and melting of sea ice","authors":"D. Zavyalov, T. Solomakha","doi":"10.15356/2076-6734-2019-1-103-111","DOIUrl":"https://doi.org/10.15356/2076-6734-2019-1-103-111","url":null,"abstract":"Numerical experiments were carried out using the thermodynamic model with the aim to optimize choice of parameterization of the density of fresh snow, its albedo, and thermal conductivity coefficient in order to reproduce the seasonal evolution of ice thickness in the North-Eastern part of the Sea of Azov. The simulation results were compared with each other as well as with the observations obtained at the costal station of the Southern Scientific Center of the Russian Academy of Sciences in the Taganrog Bay. It is shown that small differences in the schemes of parameterization of physical and thermal properties of snow and ice cover may result in significant scatter in the simulation results. To assess the quality of the forecasting of the seasonal course of the ice thickness, the standard deviation of the calculated ice thickness from the average value for the period of measuring ice thickness, the standard deviation, the correlation coefficient, and the verification of the forecast were determined. Based on the analysis of these parameters, the optimal configuration of the snow layer parameters is proposed, which allows adequate reproducing of the seasonal thermal dynamics of the sea ice thickness. For the conditions of winter 2010/2011 the most close values of calculated ice thickness to results of the measurements in the North-Eastern part of the Taganrog Bay were obtained by determining the dependence of the density of fresh snow on the temperature in the near-surface layer of the atmosphere by the algorithm CLASS, albedo of the snow surface - by the scheme EHAM5, and the coefficient of thermal conductivity of snow – by the formulas of N.I. Osokin or M. Janson. ","PeriodicalId":43880,"journal":{"name":"Led i Sneg-Ice and Snow","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2019-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66930478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-20DOI: 10.15356/2076-6734-2019-1-59-66
Р. А. Чернов, А. В. Кудиков, Т. В. Вшивцева, Н. И. Осокин
Due to climatic changes in Spitsbergen the glaciation of the Nordenskjold Land (West Spitsbergen) has significantly degraded over the past 100 years. Changes in glaciers are undoubtedly associated with intensive melting caused by a rise of summer air temperatures. Based on the results of field measurements of ablation on the East Grenford glacier, data on the ice reduction were obtained since 2004. Analysis of the results showed that magnitude of the surface ablation is in a good agreement with the values calculated by the Krenke–Hodakov formula, in which the argument is the average summer air temperature. The parabolic dependence of the Krenke-Hodakov formula with the exponent of 3.25 presented the best approximation to the field measurements for all high-altitude zones of the glacier with a correlation coefficient of 0.96. The calculated values of ablation of ice and snow were used to estimate the mass balance of the East Grenford glacier since 2004. The calculations were based on the following: measured values of jump in temperature at the boundary of the glacier, averaged values of the air temperature gradient, and averaged data on snow storage on the glacier. Data on the mass balance of the glacier is indicative of its shortening during the last decade, despite the interannual variations. In 2016, the glacier mass balance reached the lowest value equal to −1990 mm, the calculated value was equal to −1960 mm. Analysis of the data demonstrated that the average summer air temperature is the major factor affecting the glacier mass balance. These results may be useful for estimating melting and mass balance of a number of mountain glaciers of the Nordenskjold Land.
{"title":"Estimation of the surface ablation and mass balance of Eustre Grønfjordbreen (Spitsbergen)","authors":"Р. А. Чернов, А. В. Кудиков, Т. В. Вшивцева, Н. И. Осокин","doi":"10.15356/2076-6734-2019-1-59-66","DOIUrl":"https://doi.org/10.15356/2076-6734-2019-1-59-66","url":null,"abstract":"Due to climatic changes in Spitsbergen the glaciation of the Nordenskjold Land (West Spitsbergen) has significantly degraded over the past 100 years. Changes in glaciers are undoubtedly associated with intensive melting caused by a rise of summer air temperatures. Based on the results of field measurements of ablation on the East Grenford glacier, data on the ice reduction were obtained since 2004. Analysis of the results showed that magnitude of the surface ablation is in a good agreement with the values calculated by the Krenke–Hodakov formula, in which the argument is the average summer air temperature. The parabolic dependence of the Krenke-Hodakov formula with the exponent of 3.25 presented the best approximation to the field measurements for all high-altitude zones of the glacier with a correlation coefficient of 0.96. The calculated values of ablation of ice and snow were used to estimate the mass balance of the East Grenford glacier since 2004. The calculations were based on the following: measured values of jump in temperature at the boundary of the glacier, averaged values of the air temperature gradient, and averaged data on snow storage on the glacier. Data on the mass balance of the glacier is indicative of its shortening during the last decade, despite the interannual variations. In 2016, the glacier mass balance reached the lowest value equal to −1990 mm, the calculated value was equal to −1960 mm. Analysis of the data demonstrated that the average summer air temperature is the major factor affecting the glacier mass balance. These results may be useful for estimating melting and mass balance of a number of mountain glaciers of the Nordenskjold Land. ","PeriodicalId":43880,"journal":{"name":"Led i Sneg-Ice and Snow","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2019-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66930804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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