Desert dust deposition on Mt. Elbrus, Caucasus Mountains, Russia in 2009-2012 as recorded in snow and shallow ice core: high-resolution "provenancing", transport patterns, physical properties and soluble ionic composition

A record of dust deposition events between 2009 and 2012 on Mt. Elbrus, Caucasus Mountains derived from a snow pit and a shallow ice core is presented for the first time for this region. A combination of isotopic analysis, SEVIRI red-green-blue composite imagery, MODIS atmospheric optical depth fields derived using the Deep Blue algorithm, air mass trajectories derived using the HYSPLIT model and analysis of meteorological data enabled identification of dust source regions with high temporal (hours) and spatial (cf. 20–100 km) resolution. Seventeen dust deposition events were detected; fourteen occurred in March–June, one in February and two in October. Four events originated in the Sahara, predominantly in north-eastern Libya and eastern Algeria. Thirteen events originated in the Middle East, in the Syrian Desert and northern Mesopotamia, from a mixture of natural and anthropogenic sources. Dust transportation from Sahara was associated with vigorous Saharan depressions, strong surface winds in the source region and mid-tropospheric south-westerly flow with daily winds speeds of 20–30 m s−1 at 700 hPa level and, although these events were less frequent, they resulted in higher dust concentrations in snow. Dust transportation from the Middle East was associated with weaker depressions forming over the source region, high pressure centered over or extending towards the Caspian Sea and a weaker southerly or south-easterly flow towards the Caucasus Mountains with daily wind speeds of 12–18 m s−1 at 700 hPa level. Higher concentrations of nitrates and ammonium characterise dust from the Middle East deposited on Mt. Elbrus in 2009 indicating contribution of anthropogenic sources. The modal values of particle size distributions ranged between 1.98 μm and 4.16 μm. Most samples were characterised by modal values of 2.0–2.8 μm with an average of 2.6 μm and there was no significant difference between dust from the Sahara and the Middle East

High-resolution provenance of desert dust deposited on Mt. Elbrus, Caucasus in 2009–2012 using snow pit and firn core records

The first record of dust deposition events on Mt. Elbrus, Caucasus Mountains derived from a snow pit and a shallow firn core is presented for the 2009–2012 period. A combination of isotopic analysis, SEVIRI red-greenblue composite imagery, MODIS atmospheric optical depth fields derived using the Deep Blue algorithm, air mass trajectories derived using the HYSPLIT model and analyses of meteorological data enabled identification of dust source regions with high temporal (hours) and spatial (ca. 20–100 km) resolution. Seventeen dust deposition events were detected; fourteen occurred in March–June, one in February and two in October. Four events originated in the Sahara, predominantly in northeastern Libya and eastern Algeria. Thirteen events originated in the Middle East, in the Syrian Desert and northern Mesopotamia, from a mixture of natural and anthropogenic sources. Dust transportation from Sahara was associated with vigorous Saharan depressions, strong surface winds in the source region and mid-tropospheric southwesterly flow with daily winds speeds of 20–30 m s−1 at 700 hPa level. Although these events were less frequent than those originating in the Middle East, they resulted in higher dust concentrations in snow. Dust transportation from the Middle East was associated with weaker depressions forming over the source region, high pressure centred over or extending towards the Caspian Sea and a weaker southerly or southeasterly flow towards the Caucasus Mountains with daily wind speeds of 12–18 m s−1 at 700 hPa level. Higher concentrations of nitrates and ammonium characterised dust from the Middle East deposited on Mt. Elbrus in 2009 indicating contribution of anthropogenic sources. The modal values of particle size distributions ranged between 1.98 µm and 4.16 µm. Most samples were characterised by modal values of 2.0– 2.8 µm with an average of 2.6 µm and there was no signifi- cant difference between dust from the Sahara and the Middle East

ТРОПИЧЕСКИЕ ЛЕДНИКИ СЕГОДНЯ

The continuing global warming causes a significant reduction and vanishing of glaciers in the tropics. The glaciers in Africa, New Guinea, and Venezuela can completely melt during next decade under current trend in climate change.Продолжающееся глобальное потепление приводит к значительному сокращению и исчезновению ледников в тропиках. Ледники в Африке, Новой Гвинее и Венесуэле могут полностью растаять в течение следующего десятилетия при текущей тенденции изменения климата

Исследование ледников Арктики во время холодной войны: продолжение истории

During the cold war, a secret Camp Century military base was created inside the ice sheet in the north-west of Greenland. At this station, the first deep ice core was recovered. It was a beginning of a new era in paleoclimatology – a continuous record of climatic changes over the past 100 thousand years was obtained. At the end of 2018, sediments from the bottom of the Camp Century ice core were discovered at the Niels Bohr Institute in Copenhagen. Their analysis showed that the age of the glacial stratum in this part of Greenland is about 400 thousand years. The history of the Camp Century establishment and glacier ice-core drilling is shown.Рассказано о строительстве внутриледниковой станции Camp Century в северо-западной Гренландии во время холодной войны, первом в мире глубоком керновом бурении ледника и о современных исследованиях, связанных с этими работами

Use of artificial neural networks for differentiated diagnostics of ischemic and hemorrhagic perinatal affections of central neural system in newborns of different terms of gestation

The article describes neonatal and pediatric neurology researching. Among the causes of childhood disability first place belongs to diseases of the nervous system. Among perinatal brain damage leading place is occupied by cerebrovascular pathology. One of the main causes of hemorrhagic and ischemic brain damage is impaired cerebral hemodynamics. However there is no single point of view on the processes underlying the development of ischemic brain lesions and intracranial hemorrhage in premature infants. It reveals necessity of immunobiochemical neurospecific proteins defining during neonatal period. Proteins, namely neurospecific enolase, a neurotrophicfactor of nerve growth, vascularendothelial growth factor, allow early finding of pathological disorder. What is a profitable advantage compared to the widely used clinical and instrumental examination and laboratory methods to assist in determining location and extent of the brain. Articleshows importance for a multifunction-oriented model of studying peculiarities of the child, starting with finding patterns in complex processes, due to the influence of internal and external factors on the functional state of the organism based on its individual characteristics, and ending with the solution of problems of differential diagnosis. Thus enabling to seek for hidden dependencies in complex processes conditioned by internal and external factors, leading us to performing differential diagnosis. As for mathematical models and data processing algorithms, the authors used an artificial neural network. These algorithms are used when there is no a precise decision-makingsystem. The medical diagnosis of ischemic and hemorrhagic perinatal central nervous system lesions of newborns maybe added in the list problems to be solved by artificial neural networks. The paper gives valuable information aboutinvestigating child's body properties with neural networks algorithms. Results of applying these algorithms are aimed to increase accuracy of differential diagnosis of ischemic or hemorrhagic perinatal damage to the central nervous system in newborns of different gestational ages are presented

The Great Acceleration of fragrances and PAHs archived in an ice core from Elbrus, Caucasus

The Great Acceleration of the anthropogenic impact on the Earth system is marked by the ubiquitous distribution of anthropogenic materials throughout the global environment, including technofossils, radionuclides and the exponential increases of methane and carbon dioxide concentrations. However, personal care products as direct tracers of human domestic habits are often overlooked. Here, we present the first research combining fragrances, as novel personal care products, and polycyclic aromatic hydrocarbons (PAHs) as combustion and industrial markers, across the onset of the Great Acceleration in the Elbrus, Caucasus, ice core. This archive extends from the 1930s to 2005, spanning the profound changes in the relationship between humans and the environment during the twentieth century. Concentrations of both fragrances and PAHs rose throughout the considered period, reflecting the development of the Anthropocene. However, within this rising trend, remarkable decreases of the tracers track the major socioeconomic crises that occurred in Eastern Europe during the second half of the twentieth century

Применение методики компьютерной томографии для неразрушающего анализа ледниковых кернов

Computed tomography (CT) is a nondestructive high-resolution way to investigate the three-dimensional structure of samples (ice, rock, etc.). The results of CT analysis of glacial cores consisting of firn and ice extracted on the Western plateau of the Elbrus Mountain (5100–5150 m a.s.l.) in the summer of 2017 are presented in the article. The core taken from the depth of 20.31–21.87 m and consisting of three sections (average length is 52 cm each) was analyzed. In order to maintain the natural negative temperature of the glacial core, a special cryothermos has been created. It conserved the temperature at the level of −25 °C. Data on the structural features of the samples and the three-dimensional pattern of the ice-firn density were obtained. Correlations between the density and some chemical elements had been established. The CT data made it possible also to determine sizes of ice crystals. Comparison of cross sections of cores with firn and ice thin sections (30 in total) has shown that the crystal structure is best displayed in the ice inter-layers since it is impossible to determine reliably sizes of the firn grains at the given survey resolution. Also, the use of the CT method made it possible to determine inclination of the firn layers within the ice core, which is caused by the inheritance of the slope of the surface microrelief and internal inhomogeneities of the firn thickness. Calculations showed that the angle of inclination of the layers varies from 6 to 9°.Методика компьютерной томографии позволяет получить снимки послойных срезов ледникового керна с помощью рентгеновских лучей. В работе представлен анализ кернов с Западного плато Эльбруса с помощью компьютерного томографа РКТ-180. Для поддержания естественных условий керна был создан специальный криотермос, который препятствует таянию образца и изменению структуры фирна во время съёмки. Исследована внутренняя структура керна, установлены размеры кристаллов в разных слоях, найдены неоднородности и получена трёхмерная картина плотности льда

КЛИНИКО-БИОХИМИЧЕСКАЯ ХАРАКТЕРИСТИКА НЕДОНОШЕННЫХ НОВОРОЖДЕННЫХ С ЭКСТРЕМАЛЬНО НИЗКОЙ И ОЧЕНЬ НИЗКОЙ МАССОЙ ТЕЛА ПРИ РОЖДЕНИИ

The purpose of this work was to study the levels of neurotrophic factor nerve growth of the brain, the levels of vascular endothelial growth factor, the levels of neurospecific enolase and the activity of endothelin-1 in the serum of blood in preterm infants with extremely low birth weight in association with the state of the cerebral circulation, and morphologic changes in the brain. We examined 60 preterm infants, which were divided into two groups depending on weight at birth. In neonates with extremely low birth weight the dysfunction of mechanism of autoregulation in cerebral blood flow was characterized by a decrease in blood flow velocities in the anterior cerebral and in the basilar arteries, in association with low levels of trophic factors in serum to month of life and the developments of degenerative changes in the brain. In neonates with very low birth weight infants in the early neonatal period the vasospasm of cerebral vessels with the activity of neurotrophic factors to month of life gave way to the stabilization of the cerebral hemodynamics.Целью работы стало изучение сывороточного содержания нейротрофического фактора роста нервов головного мозга, васкулоэндотелиального фактора роста, сывороточной концентрации нейроспецифической енолазы и сывороточной активности эндотелина-1 у недоношенных новорожденных с экстремально низкой массой тела в ассоциации с состоянием мозгового кровообращения и морфоструктурными изменениями головного мозга. Обследовано 60 недоношенных новорожденных, которые были разделены на две группы в зависимости от массы тела при рождении. У новорожденных с экстремально низкой массой тела дисфункция механизма ауторегуляции мозгового кровотока в раннем неонатальном периоде характеризовалась снижением показателей скоростей кровотока в передней мозговой и базилярной артериях в ассоциации с низким сывороточным содержанием трофических факторов роста, что к 1 мес жизни обусловливало развитие дистрофических изменений головного мозга. У новорожденных с очень низкой массой тела в раннем неонатальном периоде вазоспазм церебральных сосудов в сочетании с активностью нейротрофических факторов роста к 1 мес жизни сменялся стабилизацией мозговой гемодинамики

Изменения ледника Чалаати (Грузинский Кавказ) с малого ледникового периода по данным космогенных изотопов (10Be) и дендрохронологии

Glacier variations over the past centuries are still poorly documented on the southern slope of the Greater Caucasus. In this paper, the change of Chalaati Glacier in the Georgian Caucasus from its maximum extent during the Little Ice Age has been studied. For the first time in the history of glaciological studies of the Georgian Caucasus, 10Be in situ Cosmic Ray Exposure (CRE) dating was applied. The age of moraines was determined by tree-ring analysis. Lichenometry was also used as a supplementary tool to determine the relative ages of glacial landforms. In addition, the large-scale topographical maps (1887, 1960) were used along with the satellite imagery – Corona, Landsat 5 TM, and Sentinel 2B. Repeated photographs were used to identify the glacier extent in the late XIX and early XX centuries. 10Be CRE ages from the oldest lateral moraine of the Chalaati Glacier suggest that the onset of the Little Ice Age occurred ~0.73±0.04 kyr ago (CE ~1250–1330), while the dendrochronology and lichenometry measurements show that the Chalaati Glacier reached its secondary maximum extent again about CE ~1810. From that time through 2018 the glacier area decreased from 14.9±1.5 km2 to 9.9±0.5 km2 (33.8±7.4% or ~0.16% yr−1), while its length retreated by ~2280 m. The retreat rate was uneven: it peaked between 1940 and 1971 (~22.9 m yr−1), while the rate was slowest in 1910– 1930 (~4.0 m yr−1). The terminus elevation rose from ~1620 m to ~1980 m above sea level in ~1810–2018.Для реконструкции колебаний ледника Чалаати в Грузии использовались космические снимки, старые карты, повторные фотографии, дендрохронология, лихенометрия и анализ космогенных изотопов. Максимальное наступание ледника в начале малого ледникового периода произошло в ~1250–1330 гг., второй максимум, когда ледник достиг почти такой же длины, датируется примерно 1810 г. С этого времени до 2018 г. площадь ледника уменьшилась с 14,9±1,5 до 9,9±0,5 км2 (33,8±7,4%, или ~0,16% год−1), а его длина сократилась на ~2280 м