Ice and Snow (E-Journal) / Лёд и Снег
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ВОЗДЕЙСТВИЕ ПОТЕПЛЕНИЯ НА ДИСКОМФОРТНОСТЬ ЖИЗНЕДЕЯТЕЛЬНОСТИ НАСЕЛЕНИЯ АРКТИЧЕСКОЙ ЗОНЫ РОССИЙСКОЙ ФЕДЕРАЦИИ
Get PDFThe present-day global warming and the rise of climate extremes are the most pronounced in the Arctic zone of theRussian Federation, and this circumstance is very important for the population of these regions. According to the zoning of theterritoryofRussiapresenting the natural conditions of the human’s life, the greater part of the Arctic zone of theRussian Federationis characterized by absolutely unfavorable and very unfavorable conditions. In this connection, estimation of the present-day climate conditions and prediction of future situation is very important for the population in many regions ofRussia, and particularly in the Arctic zone. The Nature conditions of human life in the second half of the 20th century and changes of them in the 21st one were analyzed in this work. This made possible to correct the map “Zoning of the territory of theRussian Federationon natural conditions of the human’s life" and to estimate possible changes of climate conditions by the middle of the 21st century. The results of numerical experiments performed with three models presented at the fifth phase of the coupled models comparison Project (Coupled Model Inter-comparison Project, SMIR5) were used in the work. The models are as follows: one of the Institute of Numerical Mathematics of RAS (INMCM4); the second Meteorological Office of theHadleyCenter(HadGEM2-ES), and the third – Max-Plank Meteorological Institute (MPI-ESM-LR). The most changeable climatic factors (heat, cold, and wind) were investigated. The regions of the Arctic zone of theRussian Federation, where warming is the most evident, have been established, and changes of areas with different levels of climatic discomfort during periods of current and expected climate warming have been estimated. The warming of 1991–2010 in the Western and Eastern parts of the Arctic zone of theRussian Federationresulted in that area with absolutely unfavorable conditions significantly decreased. The scale of the area reduction was found to be comparable to the change of discomfort under the «soft» anthropogenic scenario for the period 2046–2055.Продолжающееся глобальное потепление сильнее всего выражено в Арктической зоне. Бóльшая часть Арктической зоны Российской Федерации характеризуется абсолютно неблагоприятными и очень неблагоприятными условиями жизнедеятельности населения. в результате потепления в западной и восточной частях этой зоны значительно сократилась площадь с абсолютно неблагоприятными условиями. Масштаб такого сокращения сравним с изменением дискомфортности при «мягком» антропогенном сценарии для периода 2046–2055 гг
Пространственно-временная неоднородность снежной толщи по данным пенетрометра SnowMicroPen
Get PDFTe 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.Представлены результаты исследований снежной толщи, полученные на двух полигонах в Москве и Хибинах. Исследована пространственная неоднородность снежной толщи и её изменения в течение зимнего сезона. Прочность снега определяли с помощью пенетрометра высокого разрешения SnowMicroPen. Построены и проанализированы схемы развития снежной толщи и её пространственная изменчивость
АННОТИРОВАННАЯ БИБЛИОГРАФИЯ РУССКОЯЗЫЧНОЙ ЛИТЕРАТУРЫ ПО ГЛЯЦИОЛОГИИ ЗА 2016 ГОД
Get PDFThe proposed annual bibliography continues annotated lists of the Russian‑language literature on glaciology that were regularly published in the past. It includes 345 references grouped into the following ten sections: 1) general issues of glaciology; 2) physics and chemistry of ice; 3) atmospheric ice; 4) snow cover; 5) avalanches and glacial mudflows; 6) sea ice; 7) river and lake ice; 8) icings and ground ice; 9) the glaciers and ice caps; 10) palaeoglaciology. In addition to the works of the current year, some works of earlier years are added, that, for various reasons, were not included in previous bibliographies.Предлагаемая библиография продолжает ежегодные аннотированные списки русскоязычной литературы по гляциологии, которые регулярно публиковались в прошлом. Помимо работ текущего года, в списке встречаются работы более ранних лет, по тем или иным причинам не вошедшие в предыдущие библиографические списки
КОЛИЧЕСТВЕННАЯ ОЦЕНКА ОБЪЁМНОЙ ЛЬДИСТОСТИ МЁРЗЛЫХ ГРУНТОВ МЕТОДОМ ДИПОЛЬНОГО ЭЛЕКТРОМАГНИТНОГО ПРОФИЛИРОВАНИЯ
Get PDFVolumetric estimation of the ice content in frozen soils is known as one of the main problems in the engineering geocryology and the permafrost geophysics. A new way to use the known method of dipole electromagnetic profiling for the quantitative estimation of the volumetric ice content in frozen soils is discussed. Investigations of foundation of the railroad in Yakutia (i.e. in the permafrost zone) were used as an example for this new approach. Unlike the conventional way, in which the permafrost is investigated by its resistivity and constructing of geo-electrical cross-sections, the new approach is aimed at the study of the dynamics of the process of attenuation in the layer of annual heat cycle in the field of high-frequency vertical magnetic dipole. This task is simplified if not all the characteristics of the polarization ellipse are measured but the only one which is the vertical component of the dipole field and can be the most easily measured. Collected data of the measurements were used to analyze the computational errors of the average values of the volumetric ice content from the amplitude attenuation of the vertical component of the dipole field. Note that the volumetric ice content is very important for construction. It is shown that usually the relative error of computation of this characteristic of a frozen soil does not exceed 20% if the works are performed by the above procedure using the key-site methodology. This level of accuracy meets requirements of the design-and-survey works for quick, inexpensive, and environmentally friendly zoning of built-up remote and sparsely populated territories of the Russian permafrost zone according to a category of a degree of the ice content in frozen foundations of engineering constructions.На примере исследований основания железнодорожной трассы в криолитозоне Якутии предложен новый подход в применении известного метода дипольного электромагнитного профилирования для количественной оценки объёмной льдистости мёрзлых грунтов. Решение этой задачи максимально упрощено за счёт измерений только одной характеристики – вертикальной составляющей поля высокочастотного вертикального магнитного диполя
ТОЛЩИНА СНЕЖНОГО ПОКРОВА НА ЛЕДНИКЕ ВОСТОЧНЫЙ ГРЁНФЬОРД (ШПИЦБЕРГЕН) ПО ДАННЫМ РАДАРНЫХ ИЗМЕРЕНИЙ И СТАНДАРТНЫХ СНЕГОМЕРНЫХ СЪЁМОК
Get PDFSummary Comparison of two methods of measurements of snow cover thickness on the glacier Austre Grønfjordbreen, Svalbard was performed in the spring of 2014. These methods were the radar (500 MHz) observations and standard snow surveys. Measurements were conducted in 77 different points on the surface of the glacier. A good correlation (R2 = 0.98) was revealed. In comparison with the data of snow surveys, the radar measurements show a similar but more detailed pattern of the distribution of the snow cover depth. The discrepancy between the depths of snow cover on maps plotted from data of both methods did not exceed 30 cm in most parts of the glacier. The standard error of interpolation of the radar data onto the entire glacier surface amounts, on average, to 18 cm. This corresponds to the error of radar measurements of 18.8% when an average snow depth is about 160 cm and 9.4% at its maximum thickness of 320 cm. The distance between the measurement points at which the spatial covariance of the snow depth disappears falls between 236 and 283 m along the glacier, and between 117 and 165 m across its position. We compared the results of radar measurements of the pulse-delay time of reflections from the base of the snow cover with the data of manual probe measurements at 10 points and direct measurements of snow depth and average density in 12 snow pits. The average speed of radio waves propagation in the snow was determined as Vcr = 23.4±0.2 cm ns−1. This magnitude and the Looyenga and Kovacs formulas allowed estimating the average density of snow cover ρL = 353.1±13.1 kg m−3 and ρK = 337.4±12.9 kg m−3. The difference from average density measured in 12 pits ρav.meas = 387.4±12.9 kg m−3 amounts to −10.8% and −14.8%. In 2014, according to snow and radar measurements, altitudinal gradient of snow accumulation on the glacier Austre Grønfjordbreen was equal to 0.21 m/100 m, which is smaller than the average values (0.35 m/100 m). According to the results of snow measurements of 2011–2014, the average thickness of the snow cover on the glacier Austre Grønfjordbreen was by 17 cm greater than in 1979. In the very snowy year 2012, it was higher by 21.5 cm in comparison with the year 1979, and its spatial variability (standard deviation σН) had increased by 25.6 cm. Estimates of spatial and temporal variability of snow cover depth will be used to analyze the hydrothermal state of the glacier and its changes with regard to revealed features and climatic trends.Приведены результаты измерений толщины снежного покрова на леднике Восточный Грёнфьорд (Шпицберген) весной 2014 г. По этим данным оценена точность радиолокационных измерений толщины и средней плотности снежного покрова, а также их пространственная и временнáя изменчивость по сравнению со снегомерными измерениями 2011–2014 и 1979 гг
Исследование акустических свойств морского льда, покрытого снегом
Get PDFThe paper presents results of field observations of hydroacoustic characteristics of snow-covered ice cover in shallow seas of the Arctic shelf. The purpose of the research was to determine the quantitative characteristics of the reflection and absorption coefficients of sound from the bottom of the drifting ice cover, as well as the Doppler broadening of the frequency spectrum of acoustic signals depending on the thickness of the ice, the structure of the reflecting surface, the thickness of the snow cover, and the ice drift speed. The objective of the research was to obtain the data necessary for choosing optimal parameters of specialized hydroacoustic equipment designed to monitor ice conditions in the areas of operation of offshore oil and gas platforms. Researches were conducted in areas of active construction of engineering marine constructions and carrying out the transport operations. The research methodology was based on the use of an autonomous measuring complex, which for a long period was installed on the bottom of the sea at depths of 50 to 130 m. The recording system consisted of the following components: upward looking pulse sonar of the IPS-5 type produced by the Canadian company ASL; the Doppler meter of the ice drift speed ADCP (the RDI firm); and a RSM-7 electromechanical current meter. All devices operated in continuous mode with a measurement cycle of 1s, the results were recorded in memory and processed after lifting the devices to the surface. The time delays of signals reflected from the ice cover, as well as the amplitudes and variations of the sound attenuation depending on the reflectance and absorption coefficients were recorded in the memory of the up-looking sonar. Variations of time delays were used to calculate a settlement of ice formations and to determine the shape of the reflective surface, including the angles of inclination of ice keels. Doppler shift of frequency of reflected acoustic signals and broadening of the frequency spectrum were calculated using values of the ice drift speed and changes of immersion depths of hummocks. Acoustic characteristics were measured repeatedly during several seasons of each year from 2010 to 2017. This investigation made possible to obtain statistical estimates of the distributions of the reflection coefficient of the sound and the quantitative values of broadening of the frequency spectrum of acoustic signals depending on the angle of incidence of the acoustic rays, the nature of the irregularities and the structure of the reflective surfaces of ice and snow cover thickness and the drift speed. The results obtained by this research allowed reasonable choosing and calculating the basic characteristics of the hydroacoustic equipment intended for runtime diagnostics of ice cover in zones of marine engineering structures.Исследованы гидроакустические характеристики заснеженного ледяного покрова в мелководных морях арктического шельфа. Определены коэффициенты отражения и количественные значения расширения частотного спектра акустических сигналов в зависимости от характеристик морского льда со снежным покровом. Сделаны статистические оценки акустических характеристик ледяного покрова и получены значения коэффициентов отражения звука в зависимости от возрастных градаций морского льда и толщины снежного покрова
Особенности структуры пропарины в ледяном покрове, образованной выходами газа
Get PDF«Proparina» (russ) is a small hole in the ice cover formed by steaming of the ice by the gas vents. Some characteristics of this phenomenon were studied by the example of formation of one proparina found in March 2015 in the ice cover of the shallow eutrophic Lake Shakshinskoye (Trans-Baikal Region). The interest in this object is due to the fact that a proparina, unlike a polynya (small water opening in ice), is formed after the establishment of the ice cover and it can appear in those parts of a reservoir where there is no clearly expressed inflow or outflow of water. Although proparinas do often occur on some water bodies, e.g. Lake Baikal, a detailed description of their structure and process of formation is not available. Research on features of the proparina in the ice of the Lake Shakshinskoye and adjacent areas of this reservoir was carried out on March 25 and 28 in 2015. Melting at the lower and upper ice cover boundaries started at that time, and it was found that the proparina under investigation was formed in the center of a dome-shaped area where the ice thickness decreased compared to the adjoining parts within a distance of 200 meters. Gradient of the lower surface in the dome was on average 5 centimeters per 100 meters at a distance from the center. We found a narrow channel in the ice through which gas came into the proparina in the form of separate portions. The maximum recorded volume of gas that came into the open proparina reached 10 l/min. The channel is supposed to be formed at the end of winter period due to the release of gas during the melting of the lower layers of the ice cover and the subsequent movement of gas bubbles into the center of the dome. To study the ice cover structure, we measured thermo-microwave self-radiation of the “ice-water” system in the centimeter range. Such measurements allow detecting changes in ice thickness with an accuracy of 1 cm. It is assumed that the accumulation of gases under the ice causes the instability of the water column due to warming by the heat fl w from the bottom layers and initiates the circulation and, thus, formation of proparina.В ледяном покрове пресного озера Шакшинское (Забайкальский край) изучена пропарина, которая образуется после установления ледяного покрова и появляется в тех частях водоёма, где отсутствуют выраженные приток и сток вод. Пропарина размером 2 × 3 м2 сформировалась в вершине ледяного купола диаметром около 400 м. Обнаружен узкий канал, по которому в пропарину поступал газ, выделяющийся при таянии нижних слоёв ледяного покрова. Предполагается, что локальное накопление газов нарушает устойчивость столба воды из-за его разогрева потоком тепла из донных слоёв, приводит к возникновению циркуляции и образованию пропарины
ИЗМЕНЧИВОСТЬ ЗИМНЕГО СТОКА РЕКИ ОКА В ЗАВИСИМОСТИ ОТ ИЗМЕНЕНИЯ КЛИМАТА
Get PDFResponse of a river flow in a winter low-water period to the climate changes is analyzed by the example of theOkaRiver(245 thousand km2). The analysis was done for each individual month from December to March during the period 1980–2015. The data were obtained for the hydrometric section Oka–Gorbatov. The following climatic characteristics were used for the analysis: 1) the number of days with positive air temperatures; 2) the temperature of the upper soil layer; 3) the sum of precipitation (data of meteorological station); 4) water equivalent of snow (the data from the satellite ESA GlobSnow, SWE version 2). Accuracy of the satellite data was estimated with respect to the observational data. In 1981–2010, significant increase in winter runoff occurred in December and March. This period was divided into two phases: 1) the end of the 20th century which was characterized by increasing of precipitation, the soil temperature, number of days with positive temperatures, and that resulted in the growth of the water equivalent of snow; 2) the beginning of the 21st century – by significant fluctuation in precipitation, number of days with positive temperatures as well as by a drop in the soil temperature and water equivalent of snow. The runoff volume was found to be in a direct relationship with the number of days with positive temperatures, the soil temperature, the precipitation sum, and in the inverse relationship with the water equivalent of snow. Both, the regression and dispersion analyses indicated that the above set of climatic characteristics was sufficient to explain changes in the winter runoff. According to the degree of influence on the winter runoff, these characteristics can be ranked as follows: the number of days with positive temperatures; the average soil temperature; the water equivalent of snow; the precipitation sum. The effect of the water equivalent on the runoff becomes significant from midwinter and remains the most significant factor by the end of snowmelt.Определена реакция зимнего стока рек в бассейне р. Ока (притока Волги) в 1981–2010 гг. на изменение климатических характеристик: суммы осадков, числа дней с положительными температурами воздуха и температуры верхнего слоя почвы, полученных по данным метеостанций, а также водного эквивалента снега, определённого по данным спутникового зондирования. Значимое увеличение зимнего стока в бассейне Оки наблюдается в периоды становления зимнего снежного покрова и начале снеготаяния
Снежники Лагонакского нагорья (Западный Кавказ)
Get PDFThe article presents results of investigation of snowfields on the Lagonaky plateau: conditions of their formation, distribution and dynamics. Snow patches are the most characteristic elements of the high-mountain landscapes of the Lagonaky plateau. In warm seasons, they are widely distributed on local flat-topped ridges of the Lagonaky: Abadzeshsh Murzikao, Kamennoe and others, as well as on the mountain masses Fisht, Pshehasu, Oshten, and Nagoychuk. Morphological and climatic conditions of the Lagonaky Highlands are unique and favorable for formation of snow patches and long preservation of them during the spring-summer periods. These conditions are high mountain ridges with flat tops, negative karst forms of the relief as well as a favorable wind regime with long winter snow storms and heavy snowfalls. Snow patches result from snow transport and accumulation after strong snow-drift on the leeward slopes. The avalanche snow patches arise when avalanches release from steep and long slopes of the above mountain ranges. Permanent snow patches are usually formed at the same places, and duration of their existence depends on sizes and a degree of shading. At the same time, even relatively small snow patches (100–200 thousand m3) can be preserved if they are located in narrow fissures (for example, the area of the Maly Fisht Glacier). In the last 3–5 years, the permanent snow patches melt completely, which is probably a result of small amount of solid precipitation during the cold season and the relatively high air temperatures in the warm time (standard deviation is 0.8–1.0 °C above the normal).Представлены новые данные о снежниках Лагонакского нагорья. Проанализировано их распределение в пределах нагорья с учётом особенностей рельефа и ветрового режима. Отмечено значительное сокращение числа снежников и их размеров за последние годы, что обусловлено общей климатической тенденцией потепления