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Современное оледенение хребта Цамбагарав (северо‑западная Монголия) и его изменение с максимума малого ледникового периода
Get PDFCharacteristics of glacierization of the Tsambagarav mountain ridge were determined on the basis of images obtained from satellites Corona, Landsat‑5, Spot‑4, Landsat‑8 together with results of field investigations. Inventories of glaciers located on the ridge had been prepared for three time periods: 1968, 2006, and 2015. Glacierization of the ridge during the Little Ice Age (LIA) maximum was then reconstructed. In 2015, 67 glaciers formed the ridge glacierization with their total area 68.41 km2. Mean weighed altitude of the firn line averaged 3748 m. The flat‑top glaciers accounted for almost 40% of the glacierization area, and the glaciers composed 6 complexes. For the period of the LIA maximum, 73 glaciers had been reconstructed, their total area was 128.4 km2, and the calculated firn line altitude – 3583 м; these glaciers were combined into two complexes where the flat‑top glaciers predominated as well. By 1968, the area of the glacierization decreased by 36%, and the firn line altitude increased by 89 m. By 2006, area of glaciers decreased down to 71.32 km2, and the firn line altitude increased more by 60 m. Finally, in 2006–2015, area of the glacierization contracted additionally by 2.91 km2, and the firn line altitude still more increased by 16 m. Over the whole period from the LIA maximum, the flat‑top glaciers reduced the most. The general rate of contraction of glaciers tends to increase. Reconstructed rates of retreating of the valley glaciers of the Tsambagarav ridge are similar to estimates of other researchers made for the nearest centers of glacierization. Continuation of the current trend to a rise of summer temperature and a growth of precipitation should result in primary fast degradation of the flat‑top glaciers and reorganization of morphological structure of the glacierization.На основе полевых наблюдений и дешифрирования космических снимков составлены каталоги и карты современных ледников горного хребта Цамбагарав, существующих в условиях аридного климата северо‑западной Монголии. Реконструированы положение, размеры и характеристики ледников хребта в малый ледниковый период и проанализированы особенности их последующего сокращения
Экспериментальный метод прогноза лавин на основе нейронных сетей
Get PDFThe article presents results of experimental use of currently available statistical methods to classify the avalanche‑dangerous precipitations and snowfalls in the Kishi Almaty river basin. The avalanche service of Kazakhstan uses graphical methods for prediction of avalanches developed by I.V. Kondrashov and E.I. Kolesnikov. The main objective of this work was to develop a modern model that could be used directly at the avalanche stations. Classification of winter precipitations into dangerous snowfalls and non‑dangerous ones was performed by two following ways: the linear discriminant function (canonical analysis) and artificial neural networks. Observational data on weather and avalanches in the gorge Kishi Almaty in the gorge Kishi Almaty were used as a training sample. Coefficients for the canonical variables were calculated by the software «Statistica» (Russian version 6.0), and then the necessary formula had been constructed. The accuracy of the above classification was 96%. Simulator by the authors L.N. Yasnitsky and F.М. Cherepanov was used to learn the neural networks. The trained neural network demonstrated 98% accuracy of the classification. Prepared statistical models are recommended to be tested at the snow‑avalanche stations. Results of the tests will be used for estimation of the model quality and its readiness for the operational work. In future, we plan to apply these models for classification of the avalanche danger by the five‑point international scale.Обсуждаются результаты эксперимента по применению статистических методов для классификации лавиноопасных осадков и снегопадов в бассейне р. Киши Алматы в Иле (Заилийском) Алатау. Для разделения осадков на лавино- и нелавиноопасные выбраны два способа: дискриминантная функция и искусственные нейронные сети. Разработана экспериментальная модель классификации осадков и снегопадов, оценены ошибки классификации на независимом материале
Многолетняя изменчивость родниковых наледей-тарынов
Get PDFLong-term variability of large taryn-aufeises was studied for several decades in different regions of the USA (Alaska) and Russia (Chukotka, Kolyma, Southern Yakutia, Transbaikalia, and Eastern Sayan). Differences between volumes of individual ice massifs and the recorded maximal values change from 2–3 to 95–100%, and they do not depend on sizes of ice fields and their geographical locations. No statistically significant dependence of the aufeis volumes on the atmospheric precipitation amount and the air temperature was revealed in the most of the above areas. However, a general tendency for decreasing of the annual maxima of the ice reserves due to the climate warming was noticed. The long-term variations of the aufeises show existence of cycles of increase and decrease in their maximum sizes with their durations of 3, 7 and 11 years with the 25–30% amplitude of variations relative to the mean long-term values. In the Arctic areas, some of the giant aufeises do not melt completely during the summer and remain for a next winter. The volume of pereletoks (shortterm permafrost) varies within the range of 5–25%, averaging 16% of the spring ice reserves. In the southern geocryological zone, a clearly pronounced dependence of activity of the aufeis processes on the snow thickness was found: when the snow depth increased from 70 to 100 cm, volumes of aufeises decreased by a factor of three, and the aufeises disappeared completely under the thickness larger 120 cm. It should be noted that the processes producing the aufeis-forming sources of subsurface water, and the factors of their layered-ice accumulation remain almost unexplored.Рассматривается многолетняя изменчивость родниковых наледей-тарынов в разных регионах северо-восточной Азии и Северной Америки. Отклонение объёма единичных ледяных массивов от их максимальных зафиксированных значений колеблется от 2–3 до 95–100% и не зависит от размера ледяных полей и их географического положения. Для большинства участков статистически значимая зависимость объёма наледей от количества атмосферных осадков и температуры воздуха отсутствует, однако прослеживается общая тенденция сокращения максимальных в году запасов льда при потеплении климата. В многолетнем режиме выделяются циклы подъёма и спада максимальных размеров наледей продолжительностью 3, 7 и 11 лет. Уменьшение объёма родниковых наледей согласуется с другими фактами современной дегляциации криосферы
Химический состав аэрозоля в приземном слое прибрежной зоны Восточной Антарктиды
Get PDFChemical composition of aerosol in the ground layer of the coastal zone in East Antarctica is analyzed in the article. The aerosol samples were taken in 2006–2015 during seasonal works of the Russian Antarctic Expeditions (RAE), namely, these were 52nd–53rd, 55th, and 58th–60th expeditions. Samples were taken in the 200‑km band of the sea-shore zone along routes of the research vessels (REV) «Akademik Fedorov» and «Akademik Treshnikov» as well as on territories of the Russian stations Molodezhnaya and Mirny. Although the results obtained did show the wide range of the aerosol concentrations and a certain variability of their chemical composition, some common features of the variability were revealed. Thus, during the period from 2006 to 2014 a decrease of average values of the sums were noted. Spatially, a tendency of decreasing of the ion concentrations was found in the direction from the station Novolazarevskaya to the Molodezhnaya one, but the concentrations increased from the Molodezhnaya to the station Mirny. The sum of ions of the aerosol in the above mentioned coastal zone was, on the average, equal to 2.44 μg/m3, and it was larger than that on the territory of the Antarctic stations Molodezhnaya (0,29 μg/m3) and Mirny (0,50 ág / m3). The main part to the sum of the aerosol ions on the Antarctic stations was contributed by Na+, Ca2+, Cl−, SO4 2−. The main ions in aerosol composition in the coastal zone are ions Na+ and Cl−. The dominant contribution of the sea salt and SO4 2− can be traced in not only the composition of atmospheric aerosols, but also in the chemical composition of the fresh snow in the coastal areas of East Antarctica: at the Indian station Maitri, on the Larsemann Hills, and in a boring located in 55.3 km from the station Progress (K = 1.4÷6.1). It was noted that values of the coefficient of enrichment K of these ions decreases as someone moves from a shore to inland. Estimation of contributions of the continental and maritime factors to formation of the aerosol chemical composition revealed higher enrichment ratios for K+, Ca2+, SO4 2− (K = 3.6÷13.0). This reflects not only influence of the natural sources, but the intensity of human activities on the Antarctic continent as well. The elemental composition of solid aerosols was also analyzed. The largest concentrations were determined for Zn, Al and Fe. The ratio of concentration of the elements in both the soluble and insoluble phases of the aerosol showed that 84.1% of the total amount of the elements was contained in a water-insoluble state. Fractional relation between the element concentrations changed in different phases from 16 to 98%. High enrichment of the aerosol particles by Zn, Cu, Cr, Ba, Pb, Ni,Se, As, Cd (the enrichment factors = 27÷26 445) had been revealed. The content of dominant chemical components (Na+, Cl−, Zn, Fe), factors and coefficients of the element enrichment in the aerosols as well as in fresh snow of the coastal zone of East Antarctica are indicative of the identity of sources where their composition is formed.Рассмотрена временнáя и пространственная изменчивость химического состава атмосферного аэрозоля, отобранного в период сезонных работ 52, 53, 55, 58–60‑й РАЭ по маршруту следования НЭС «Академик Федоров» и «Академик Трешников» от станции Новолазаревская до станции Мирный. Заметное снижение суммы ионов в аэрозоле в 2007–2008 гг. хорошо согласуется с исследованиями в районе Восточной Атлантики и связано с гидрологическими процессами в Атлантическом океане. Установлено высокое обогащение аэрозольных частиц Zn, Cu, Cr, Ba, Pb, Se, As, Ni, Cd. Содержание преобладающих химических компонентов (Na+, Cl−, Zn, Fe), факторы и коэффициенты обогащения элементов (ФО = 27÷26 445) и ионов (K = 3,6÷13,0) в аэрозоле в поверхностном и свежевыпавшем снеге (K = 1,4÷6,1) прибрежной части Восточной Антарктиды свидетельствуют об идентичности источников формирования их состава
Динамика параметров снежного покрова, влияющих на устойчивость многолетней мерзлоты на архипелаге Шпицберген
Get PDFClimate 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.Рассмотрены аномальные и экстремальные значения толщины снежного покрова, сроков его установления и схода, продолжительности залегания, динамики снегонакопления, продолжительности оттепелей и количества жидких осадки на архипелаге Шпицберген за 1973-2013 гг. В настоящее время более 60% толщины снежного покрова формируется в первой трети холодного периода года, что влияет на промерзание сезонного талого грунта
Ледники северного массива гор Сунтар-Хаята: современное состояние и динамика с конца 1950-х годов
Get PDFThe estimation of glaciers of the Suntar-Khayata Mountains (the Northeastern Siberia) in the context of previously published data is presented. Under the background of current warming the glaciers in this region retreat enough quickly, they decrease not only in a real size, but also by the ice thickness. In this paper the mean summer temperature and solid precipitation of the key factors for glaciation, which indicate unfavorable conditions for the glacier existence at present time are presented as spatial distribution of trends (for 45 years, until 2012). The glaciers of the northern massif of the Suntar-Khayata have a negative ice mass balance as their entire surface is below the equilibrium line altitude. Mean thickness of superimposed ice on the glaciers of this massif was about 17 cm. Based on the assumption of climate variation in the Northern Pacific data it is suggested about the beginning of more favorable climatic conditions for the Suntar-Khayata glaciers.В основу работы положены результаты обработки космических снимков Bing Map 2011 г. и материалы полевого сезона 2013 г. Оценено состояние ледников северного массива гор Сунтар-Хаята в продолжение ранее опубликованных работ [4, 5]. На фоне потепления на Северо-Востоке России ледники исследуемого района достаточно быстро деградируют, уменьшается не только их площадь, но и толщина. Полевые исследования показали, что все ледники этого массива в 2011–2013 гг. имели отрицательный баланс массы. За время с малого ледникового периода ледники № 28–31 потеряли около 0,38 км3 льда
50 лет геофизических исследований ледников в Институте географии
Get PDFIn 1967‑2015, Institute of Geography of the USSR/Russian Academy of Sciences together with other organizations carried out field expeditions in different areas of mountain and polar glaciations in many regions: the Polar Urals, Caucasus, Pamir, Zailiysky and Jungar Alatau, Tien‑Shan, Pamir‑Alai, the Kamchatka Peninsula, the Pyrenees, the Arctic – Spitsbergen, Novaya Zemlya, Franz Josef and Severnaya Zemlya, and Antarctica – on the ice flow B, and in the sub‑Antarctic – Islands King George, Galindez, and Livingston. The gravimetric and ground and aerial radar observations were made in these expeditions. About 300 glaciers of different morphological types and sizes with cold, subpolar and temperate thermal regime were studied. Basic results of these studies are the following: (1) the new data on the ice thicknesses, ice volumes, subglacial relief, internal structure, and thermal state of the glaciers were obtained; (2) the two‑layered (polythermal) glaciers consisting of the upper layer of cold ice and the lower layer of temperate water‑filled ice had been revealed in Svalbard for the first time; spatial distribution of cold, polythermal and temperate glaciers had been determined; (3) the evidences were obtained that measured changes in thickness of the upper cold ice layer in polythermal glaciers can be used to estimate the long‑period variations of regional climates and serve as regional paleothermometers; (4) methods for estimating the water content in temperate and polythermal glaciers from the RES data were developed; and its space‑time variations in temperate ices of the Svaldbald glaciers were estimated since even small water content inside of them can noticeably change their dynamic behavior; (5) methods for estimating the ice volume within glaciers in large regions of mountain and polar glaciations had been created; the ice storages were estimated in Svalbard, Franz Josef Land, Dzhungrsky Alatau, the Great Caucasus, and Mt. Elbrus; (6) detailed data on the ice thicknesses and the subglacial relief had been obtained for 40 glaciers in framework of different national and international programs and projects; the data can be used to solve a wide range of practical and theoretical problems, including numerical modeling. These studies demonstrated the following: (1) the use of monopulse radars VIRL‑6 and VIRL‑7 of decameter range (the central frequency is 20 MHz) with digital recording of the radar and GPS data is quite efficient for ground‑based and airborne (from helicopters) radio‑echo sounding of mountain and polar glaciers with their ice thicknesses up to 500–600 m; (2) it was found that thicknesses of glaciers in the Caucasus and Tien Shan can reach 330–430 m, while in regions of mountain, ice‑sheet and transitional glaciation on the Spitsbergen Archipelago – 300, 560 and 600 m, respectively, on the ice caps of the Franz‑Josef Land and Severnaya Zemlya – 450 and 813 m, and on King George and Livingston Islands (Sub‑Antarctica) – 330 and 500 m; (3) large parts of ice caps and outlet glaciers in Svalbard, Franz Josef Land, Severnaya Zemlya which beds were located below the sea level were found. Precisely these parts can be undergone quick shortening due to climate warming, and, thus, cause formation of icebergs making threats for ships and gas‑oil marine platforms in the Barents and Kara seas; (4) data of the measurements made possible to calculate volumes of a number of investigated glaciers and ice caps and to estimate the ice storages in large areas of mountain and polar glaciations (the Jungar Alatau, Great Caucasus, Spitsbergen, Franz Josef Land); (5) decreasing of glacier volumes on the Franz Josef Land and some Spitsbergen glaciers for the last decades had been estimated. Analysis of the data obtained had shown that considerable part of polythermal glaciers in Spitsbergen belong to type of surging glaciers; they have the winter englacial runoff and form the near‑glacier icings. It allows considering such glaciers as dynamically unstable, predisposed to surges as well as possible sources of winter water supply and additional sources of paleoinformation about long‑period variations of regional climate.Рассказано об истории и основных результатах геофизических исследований ледников, выполненных в Институте географии АН СССР/РАН в период с 1966 по 2016 г. группой специалистов по изучению толщины и строения ледников с применением геофизических методов. Такие данные необходимы для оценки запасов пресной воды в ледниках и их вклада в изменение уровня Мирового океана, а также для прогнозирования и реконструкции динамики ледников
Перспективы российских полярных исследований в свете подготовки Международной полярной партнерской инициативы
Get PDFThis document was discussed and adopted at the Polar Conferences Sochi in 2014 and in 2015.Этот документ обсуждён и принят на полярных конференциях в Сочи в 2014 и 2015 г
Рецензия на книгу Н.А. Шполянской «Плейстоцен-голоценовая история развития криолитозоны Российской Арктики «глазами» подземных льдов»
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Каменные глетчеры хребта Сунтар‑Хаята
Get PDFThe remote map‑making technique and results of field investigations made possible for the first time to reveal a great number of rock glaciers within the area of the Suntar‑Khayata Range (North‑East Asia). A total of 540 formations were identified. Among them, 47 rock glaciers were classified as corrie (cirque) tongue‑shaped formations and 493 ones – as niche lobe‑shaped (single‑ and multi‑lobe) rock glaciers. Occurrence of such formations is 8.4/100 km2, that is the largest in the North‑East Asia. The rock glaciers in this region are found within a range of true altitudes from 1297 up to 2402 m asl. The majority of active features, however, are confined to the interval between 1500 and 1900 m asl. Rock glaciers occur in the altitudinal range of 1297 to 2402 m asl. The majority of active features, however, are confined to the interval between 1500 and 1900 m asl, and the main part of active formations is located within the range of 1500‑2500 m. The frequency analysis of true altitudes of the rock‑glacier occurrence indicates that their formation can be caused by the hypsometry of the region relation to morphoclimatic zonality.Методы дистанционного картографирования и результаты экспедиционных обследований позволили впервые установить значительное число каменных глетчеров в пределах хребта Сунтар‑Хаята. Всего идентифицировано 540 каменных глетчеров. Установленные каменные глетчеры различных типов распространены в интервале высот 1300–2400 м над ур. моря и представляют собой индикаторную формацию горной криолитозоны и перигляциального пояса