Ice and Snow (E-Journal) / Лёд и Снег
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Антропогенное влияние на микроклимат и оледенение Кунгурской Ледяной пещеры в период максимальной туристической нагрузки
Get PDFThe Kungur Ice Cave is visited by thousands of tourists every year, so the question of anthropogenic influence on changing its state is acute. Snow and ice formations are the main attraction of the cave. From the moment of discovery and improvement of the cave, the thickness of glaciation began to depend not only on natural, but also on technical and anthropogenic conditions. First, this is a change in the temperature of the outside air, the annual rise of underground and surface waters (the Sylva River), the construction of inlet and outlet tunnels, artificial ventilation, and the number of tourists. To assess the impact of the flow of tourists on the microclimatic characteristics of the Cave, the staff of the Kungur Stationary Laboratory conducted research during the period of maximum anthropogenic load in the summer of 2022. The data analyzed in this article made it possible to clarify that the existing tourist load has an insignificant impact on the microclimate of the Cave. After the passage of each group of tourists, the air temperature in the grottoes slightly increases (by a maximum of 0.1–0.2°C) but is restored during the daytime within 4–12 minutes, and at night the temperature regime is completely restored. The maximum tourist load per day is 825–925 people or more, depending on the operating mode of the Cave. Thus, the visiting regulations and the allowed throughput of the cave are currently chosen correctly. The number of tourists is not so large as to limit the visit to the Cave to protect the ice formations, especially since the first-year ice is renewed every winter.По данным проведённых в летнее время исследований в Кунгурской Ледяной пещере, во время максимальной туристической нагрузки, сделаны выводы об антропогенном влиянии на микроклимат и оледенение пещеры. Рассмотрены основные виды воздействия человека на подземную среду, особое внимание уделено тепловому воздействию на изменение температурного режима и масштаба оледенения в существующих условиях эксплуатации Кунгурской Ледяной пещеры
Изменчивость ледяного покрова в Печорском море и её корреляция с температурой поверхности Баренцева моря по данным спутниковых наблюдений и реанализа
Get PDFVariability of the Pechora Sea ice cover and the Barents Sea surface temperature during the season from October to June in 2002–2022 (except the season of 2011/2012) was studied on the basis of satellite observations and reanalysis ERA5. Influence of the sea surface temperature on the ice cover was also analyzed but without considering the other hydrometeorological parameters. Areas of the sea ice cover characteristics were calculated using data on the sea ice closeness obtained from the Advanced Microwave Scanning Radiometer 2 measurements. To analyze the variability of sea surface temperature, we used the average daily data of the European Centre for Medium-Range Weather Forecasts ERA5 reanalysis obtained by averaging hourly data. To study the spatial and temporal variability of sea ice cover and sea surface temperature, fields of daily averaged parameters were mapped. These maps and values of areas of the sea ice cover were analyzed. This made possible to reveal regularities of development of the sea ice processes in the Pechora Sea, to calculate the general trend of the sea ice area change over the considered period of time, and to divide the Barents Sea into four sectors with significantly different average values of the sea surface temperature: southwestern, northwestern, southeastern, northeastern ones. The seasonal and interannual variabilities of the Pechora Sea ice cover and the Barents Sea surface temperature were analyzed. To study the effect of sea surface temperature in different sectors of the Barents Sea on the sea ice area, the method of statistical analysis (Pearson’s linear correlation) was used for the monthly average data and the data, averaged over the sea ice season (from October to June) with different time lags. Significant correlation coefficients were obtained only for a two-month lag. With such a lag, high values of the inverse correlation coefficients were revealed between the sea surface temperature in the southwestern (up to –0.8) and northwestern (up to –0.6) sectors of the Barents Sea and sea ice area of the Pechora Sea, while in other sectors the correlation was significantly smaller or even below the significance level. В работе анализируется изменчивость площади морского льда в Печорском море по данным спутникового пассивного микроволнового зондирования и температуры поверхности Баренцева моря в его разных районах по данным реанализа ERA5 за 2002–2022 гг. Выявлена значительная корреляция между этими параметрами при использовании временнóго лага в два месяца и температуры Баренцева моря в его юго-восточном и юго-западном районах
Причины неопределённости в палеоклиматических реконструкциях по изотопному составу кислорода ледникового льда Эльбруса (Западное плато)
Get PDFA study of the isotope signature of glacial ice in the Western Elbrus Plateau (the Caucasus) was made on the basis of five ice cores obtained in different years with high resolution. It was shown that the isotopic characteristics of ice are associated with the processes of accumulation and wind scouring of snow. Three ice cores were obtained in 2013 (C–1, C–2 and C–3), one in 2017 (C–4) and one more in 2018 (C–5). Core sampling was performed with a resolution of 5 cm. Isotopic analysis was done at the CERL laboratory (AARI) using a Picarro L2130-i isotope analyzer, the accuracy was 0.06‰ for δ18O and 0.30‰ for δ2Н. The values of d18О and δ2Н of the ice of the Western Plateau generally vary from –5 to –30‰ and from –18.7 to –225.8‰, respectively, with well-defined seasonality. Comparison of the isotope record for all cores showed that the differences in accumulation for individual seasons reach 0.3 m w. eq., differences in accumulation for individual seasons averaged over 5 years is approximately 0.2 m w.eq. The absolute differences in the average seasonal values of d associated with wind scouring and spatial redistribution of snow (deposition noise), averaged over 5 years, reached 1.38‰. The irregularity of precipitation amount within the season and errors in core dating are an additional contribution to non-climate variance (noise of definition). The absolute difference in the average seasonal values of δ18O associated with this type of noise averaged over 5 years is 1.7‰. Thus, the total uncertainty for two different types of noise can be estimated at 2.2‰, which is about 20% of the annual seasonal amplitude of δ18O values of the glacier ice in the Western Plateau (the average difference between the δ18O values of warm and cold seasons is ~10–11‰). One of the problems of linking the isotope record to the annual temperature record at the weather station was solved by using ammonium concentrations for dating the C-1 ice core and calculating the “ide+al” annual variation of δ18O values by a cosine function of the annual amplitude. Using ammonium ion (NH4) concentration each annual layer in C-1 ice core was divided into two parts associated to snow deposition in winter and in summer. It also showed δ18O values associated to change of seasons. The calculation of the cosine function showed the simplified δ18O values for each month of a particular year, due to which the δ18O values of the season boundaries in the ice core were linked to calendar months. This assimilation allowed us to compare the obtained average seasonal values of δ18O from the core with instrumental observations at the Klukhorskiy Pass meteorological station. The δ18O values of winter seasons have a weak relationship with surface temperatures, not only due to wind erosion, but also due to the high interannual variability of snow accumulation. At the same time, the average δ18O values of the warm seasons are significantly positive correlated with surface temperature (r = 0.7, p = 0.1), so ice core δ18O records can be used as a temperature proxy of the warm period.Выполнены измерения изотопного состава кислорода в неглубоких кернах, полученных в разные годы на Западном плато Эльбруса. Совмещение изотопной записи (δ18O) по глубине для трёх кернов показало, что в пределах локального участка Западного плато до 330 мм вод. экв. в слое годовой аккумуляции, т.е. около 20% средней годовой аккумуляции может быть сформировано за счёт перераспределения выпавшего снега. Неточности в реконструкции температур по среднесезонным значениям δ18O связаны с изменением сезонных пропорций в накоплении снега и с неравномерностью выпадения осадков внутри сезонов.
Последнее оледенение и ледниково-подпрудные озера в юго-восточной части Горного Алтая
Get PDFThe palaeogeographic scheme of the distribution of glaciers and ice-dammed lakes in the Altai during the last global glaciation (MIS-2) was compiled based on a detailed large-scale geomorphological survey. Analysis of geomorphological traces of glaciers of this time indicates that they occupied smaller areas than those of the first Late Pleistocene glaciation. By this means, the ice dams created by them were smaller that resulted in small sizes of ice-dammed lakes. The preserved levels of terraces indicate that during the first Late Pleistocene glaciation in the Kurai-Chuya depression system the ancient lake was the only one with a level of 2250 m and a total volume of 1.70 km3. During the second Late Pleistocene glaciation in the south-east Gorny Altai, another separate lake existed which was the Bartal-Kurai Lake with a level of 1700 m and a volume of 45 km3. This lake was dammed by the Mashey Glacier, which descended from the northern slopes of the North Chuaya Range. In the Chuya Depression, the existence of a landslide-dammed lake with a volume of 0.7 km3 and a level 1.750 m has been found. Its formation was not associated with glaciers of the MIS-2 stage. Direct dating of the last ice-dammed lake in the Chuya Depression with a level of 1950 m and a volume of 140 km3 has not yet been determined. This lake was dammed by the Kuehtanar Glacier, which descended from the southern slope of the Kurai ridge. The volume of ice-dammed waters of the MIS-2 time was an order of magnitude smaller than it was in the first Late Quaternary glaciation. This explains the much lower intensity of erosive and accumulative processes associated with the mega-flood occurred due to the breakthrough of the lakes during MIS-2.Составлена палеогеографическая схема распространения ледников и ледниково-подпрудных озёр времени последнего глобального похолодания (МИС-2) на основе детальной геоморфологической съёмки крупного масштаба. Реконструированы уровни и объёмы ледниково-подпрудных озёр во время первого и второго позднеплейстоценового оледенения, а также завально-подпрудного озера, формирование которого не связано с ледниками эпохи МИС-2
Высота снежного покрова в лесу и поле на равнинной территории России при современном климате
Get PDFAverage values of maximum snow depths (MaxSD) estimated separately under conditions of forests and fields on lowlands of Russia were compared during the past 29 years. It was found that MaxSD in the fields for the current climatic period 1991–2020 increased by 5% compared to the period 1966–1990 and decreased by 8% in the forests. For the periods 1966–1990, 1981–2010, and 1991–2020, the ratio of MaxSD in a forest to similar one in a field (which we refer to as the snow survey coefficient) has been constantly decreasing. The snow survey coefficients for these periods were equal to 1.24; 1.12 and 1.08, respectively. In 1991–2020, the greatest values of this ratio were obtained in the northeast of the European part of the territory of Russia (ETR) and in the south of Western Siberia, where the maximum thickness of snow cover in the forest was found to be significantly higher than in the field. The lowest values were observed in some areas of the ETR center as well as in south-east and south-west, and in the south of Eastern Siberia. Here, for the periods 2001– 2010 and 2011–2020, the values of the snow survey coefficients were estimated as 1.07 and 1.03 respectively. The coefficient for 1991–2020 decreased, on average, by 12% compared to 1966–1990. The maximum decrease in this ratio – by 15–25% – occurred in the south-west of Eastern Siberia and in a larger part of the ETR in the south. In 2011–2020, the MaxSD values increased in forests in the south-east of the ETR by 5– 15%, and decreased in the south-west and the west of the ETR by 15–25% compared to 1966–1990. At the same time in fields, the MaxSD increased by 15–30% in the east of the ETR and the south of Siberia and decreased in the center and south-west of the ETR by 10–15%. The average value of the MaxSD in the field for the period 2011–2020 increased by 6% compared to 1966–1990 and decreased in the forest by 10%. Relative to other periods, the greatest increase in MaxSD was observed in 2001–2010. In the period 2011–2020, the MaxSD both in the forest and in the field mainly decreased relative to the period 2001–2010. In the current climatic period (1991–2020), the tendency for equalization of the MaxSD in forests and fields has been confirmed.Проведено сравнение средней многолетней максимальной высоты снежного покрова в лесу и поле за разные климатические периоды. Среднее значение максимальной высоты снежного покрова в поле за современный климатический период 1991–2020 гг. увеличилось на 5% по сравнению с базовым историческим климатическим периодом 1966–1990 гг. и снизилось в лесу на 8%. Отношение максимальной высоты снежного покрова в лесу к её значению в поле за эти периоды составило 1.08 и 1.24 соответственно
Изотопно-гидрологические исследования в бассейне р. Талдура (Южно-Чуйский хребет, Центральный Алтай)
Get PDFStable isotopes investigation was carried out in the territory of the Yuzhno-Chuya Ridge (Central Altai) during the ablation season of 2022. Samples were taken to determine the contribution of meltwater and precipitation to feeding of water bodies. The main research objects are Nekrasov glacier – Tamozennoye Lake system and Taldura River. In the basin of Lake Tamozennoye, the average ice δ18O of the Nekrasov glacier (‒17.3%) was obtained. Based on the isotopic composition of ice and precipitation, it was estimated that in the stream flowing into Lake Customs, the contribution of glacier meltwater varies from 28 to 67%, on average 54%. For a stream flowing out of a lake, the proportion of meltwater is higher: 48–72, 61% on average. First of all, meltwater enters the lake by filtration through the moraine, and not by surface runoff. Along the Taldura River, δ18O does not change significantly (δ18O –16.58 … –16.84%) for 38 km before the Taldura River confluence into the Chagan River. This indicates the complete predominance of glacier meltwater in the river feeding in the middle of the ablation season. Repeated sampling of water from the Taldura River 5 km from the edge of the glacier showed, that the effect of precipitation can be traced in the isotopic composition of river water, but it does not exceed 20%.Представлены результаты изотопных исследований в долине р. Талдура. Определены изотопные характеристики льда ледника Некрасова и воды рек и ручьёв в середине сезона абляции. Показано преобладание ледникового питания на всём протяжении р. Талдура. Установлено, что талые воды менее крупного ледника Некрасова оказывают меньшее влияние на питание моренного оз. Таможенное по сравнению с влиянием талых вод ледника Большая Талдура на сток р. Талдура
Пространственно-временнáя неоднородность значений δ18O и структуры снежной толщи на территории метеообсерватории МГУ
Get PDFThe isotopic composition (δ18O values) of snow layers, constructing snow cover to the time of reaching maximum snow water equivalent (SWE), was compared with the isotopic content of snow precipitated over the whole the winter season 2018/19 on the territory of the Meteorological Observatory of the Lomonosov Moscow State University (Moscow, Russia). Snow-sampling was carried out in a trench 20 m long simultaneously with detailed measurements of spatial variability of the structural characteristics of snow depth. Sampling was conducted for each precipitation event over the winter season, with the amount of precipitation also documented. It was found that the spatially-distributed enrichment with heavy oxygen isotopes along the trench fell within the range of 0–3.5‰, with average values for the four main formed snow layers changing from 1.3 to 2.5‰. The enrichment was not much dependent on the age of snow layer in the snowpack, and it was even more pronounced in the upper layers. This suggests that the post-precipitated change in the isotopic composition of snow cover for the conditions of the investigated site mainly took place when the snow was exposed to the atmosphere (due to sublimation and evaporation), while the processes of dry and wet metamorphism were either less important or even led to leveling the effects of isotopic fractionation. A positive correlation was found between the isotope composition of snow and the spatially varying snow density in each layer. This is most probably related to involvement of wind influence into the snow accumulation resulting in more dense snow. The spatial variability of the isotope composition of snow in each layer was smaller than changes in snow density and snow water equivalent.Представлены результаты сравнения изотопного состава (значений δ18O) разновозрастных слоёв снега, слагающих снежную толщу к моменту максимального водозапаса, с изотопным составом осадков, сформировавших эти слои в течение зимнего сезона 2018/19 г. на территории метеообсерватории МГУ. Установлено, что ожидаемое утяжеление изотопного состава от времени выпадения до времени отбора образцов практически не зависело от возраста слоёв
Основные факторы формирования субаэральных таликов в рамках одномерной математической модели на примере района реки Шестаковка, Центральная Якутия
Get PDFThis study presents a mathematical model of heat transfer in a subaerial talik. The model is based on the concepts presented in classical works on permafrost, as well as on the results of geological and geophysical research carried out in the Shestakovka River basin (Central Yakutia). This model is based on the solution of the classical Stefan problem on the moving of the phase transition boundaries for a multilayer and multiphase medium. The solution was calculated on a unstructured mesh. When the phase boundaries move, thawed or frozen layers of soil are formed or wedged out. The layers include: snow cover, seasonally thawed soil, seasonally frozen and frozen sand deposits, as well as soil-vegetative layer. Published empirical relationships were used to calculate thermophysical coefficients, which are presented in this article. Simple variants of the model were considered to clarify the contribution of various factors to the process of formation and evolution of taliks. It has been established that the presence of snow cover and soil-vegetative layer have the most significant effect on the formation of taliks. Calculations show that taliks are formed in the first years of the modeled period, in the presence of snow and the absence of soil-vegetative layer. The soil-vegetative layer, depending on its composition and moisture content (ice content), can prevent the formation and development of taliks. The authors do not consider cases where shrubs contribute to snow accumulation. The humidity and iciness of the layer of sand sediments located in Central Yakutia have practically no effect on this process.На основе математического моделирования и численных экспериментов дана оценка влияния разных факторов на формирование и термический режим субаэральных таликов. Различные модельные сценарии показали, что наибольший вклад в формирование и развитие таликов вносит снежный покров, препятствующий выхолаживанию грунта в зимний период. Наличие напочвенного слоя с определенными теплофизическими параметрами может препятствовать формированию талика. Рассмотрено влияние теплофизических параметров напочвенных покровов на формирование талика
Гляциологические исследования Института географии РАН на Эльбрусе в 2023 г
Get PDFIn June 2023, mass-balance and meteorological observations on Elbrus were expanded: monitoring of the Mikelchiran glacier on the northern slope of the volcano was added to the permanent observations on the southern slope (Garabashi glacier). Such synchronized observations on the opposite macro-slopes of Elbrus have not been carried out before.В июне 2023 г. были расширены масс-балансовые и метеорологические наблюдения на Эльбрусе: к постоянным наблюдениям на южном склоне (ледник Гарабаши) добавлен мониторинг ледника Микельчиран на северном склоне вулкана. Ранее подобных синхронных наблюдений на противоположных макросклонах Эльбруса не проводилось