High Mountain Regions Research Articles

Brief communication: Application of a muonic cosmic ray snow gauge to monitor the snow water equivalent on alpine glaciers

Abstract. Monitoring the snow water equivalent (SWE) in the harsh environments of high mountain regions is a challenge. Here, we explore the use of muon counts to infer SWE. We deployed a muonic cosmic ray snow gauge (μ-CRSG) on a Swiss glacier during the snow-rich winter season 2020/21 (almost 2000 mm w.e.). The μ-CRSG measurements agree well with measurements by a neutronic cosmic ray snow gauge (n-CRSG), and they lie within the uncertainty of manual observations. We conclude that the μ-CRSG is a highly promising method to monitor SWE in remote high mountain environments with several advantages over the n-CRSG.

Distinct transport mechanisms of East Asian dust and the impact on downwind marine and atmospheric environments

East Asian dust episodes have a multitude of impacts, including on human health, environment, and climate over near-source and receptor regions. However, the mechanistic understanding of the synoptic conditions of these outbreaks at different altitude layers, and their eventual environmental impacts are less studied. The present study analyzed the synoptic transport patterns of East Asian dust during multiple dust generation episodes that occurred over only a few days apart in northern China, and which eventually delivered high PM10 concentrations to surface level and high-altitude locations in Taiwan. Whether the dust plume was uplifted ahead of or behind the 700 hPa trough over East Asia determined its trajectory and eventual impact on the environment downwind. The total dust (iron) deposition over the ocean surface preceding arrival to Taiwan was 2.4 mg m−2 (0.95 μg m−2) for the episode impacting the surface level and 5.0 mg m−2 (4.6 μg m−2) for the episode impacting high-altitude Taiwan. Dust deposition in marine areas east of China was more intense for the higher altitude transport event that was uplifted behind the 700 hPa trough and resulted in twice higher marine Chl-a concentrations. Furthermore, we estimated a dust-induced direct radiative effect over a high mountainous region in Taiwan of −6.2 to −8.2 W m−2 at the surface, −1.9 to −2.9 W m−2 at the top of the atmosphere and +3.9 to +5.3 W m−2 in the atmosphere. This dust-induced atmospheric warming and surface cooling are non-negligible influences on the atmospheric thermal structure and biogeochemical cycle over the western North Pacific. Overall, this study highlights the significant impacts of dust particles on the marine ecosystem and atmospheric radiation budget over the downwind region, thus lays the foundation for linking these impacts to the initial synoptic conditions in the source area.

Rock mass characterisation and distinct element modelling of a deep-seated rock slide influenced by glacier retreat

The active deep-seated Marzellkamm rock slide is situated in the high mountainous region of Tyrol (Austria), which has been subjected to the most recent deglaciation since the Little Ice Age (LIA). This study presents the investigation of initial rock slide formation and deformation mechanisms with respect to the structural geological inventory and the recent glacier retreat of approximately 2.2 km in length and 160 m in thickness since 1893. An integrated approach comprising field-based rock mass characterisation, glacier reconstruction based on historical maps (1893–1949) and remote sensing data (1953–2017), multi-temporal morphological analysis (1971–2019), and 2D distinct element modelling was applied.We show that deformation features mapped on the surface are reproduced by numerical modelling, and that (i) rock slide formation and slab development originates along pre-existing fault zones, (ii) a sliding mechanism occurs along a predefined fully persistent, curved but non-circular basal shear zone, and (iii) meso-scale fractures (e.g. joints) have only a minor impact on rock slide formation.Glacier reconstruction and deformation analysis show that increased slope displacements are directly associated with accelerated deglaciation rates between 1893 and 2017. Stable slope conditions were obtained by modelling as long as half to one third of the lower slope was covered by glacier ice, i.e. before the 1969 glacier stage. Rock slide movement is assumed to have initiated during the basal shear zone formation from 1949 onwards. Triggered by the general sliding movement, shear displacement along pre-existing fault zones led to the formation of rock slide structures and the separation in individual slabs and blocks.Our study shows that detailed geological mapping and deformation monitoring in combination with numerical modelling techniques can create a promising rock slide model.

Causes for the increase of early-season freezing events under a warmer climate at alpine Treelines in southeast Tibet

Few data have demonstrated why early-season freezing events may increase under a warmer climate at alpine treelines, which is critical to understand the key limiting factors determining treeline dynamics under future climate warming. Here we test the hypothesis that the increase of early-season freezing events under a warmer climate is mainly associated with advanced onset of growing season and enhanced radiative cooling effect in the pre-monsoon season. We conducted 11-year observations of microclimate factors across north-facing and south-facing treelines in the Sergyemla Mountains, southeast Tibet. We found that the frequency, intensity, and duration of early-season freezing events were generally higher under a warmer climate on the south-facing slope or in the warmer years within a slope, in which the frequency of early-season freezing events significantly increased with increasing annual mean air-temperature. During 2006–2016, the frequency, intensity and duration of early-season freezing events typically showed a negative correlation with the onset date of growing season, while their frequency was positively correlated with the early-season global radiation. In each of both slopes, global radiation was significantly higher and long-wave radiation balance was much more negative on days with daily minimum air-temperature (Tmin) < 0 °C than with Tmin > 0 °C, indicating the generality of radiative cooling effect on early-season freezing events at high elevations. Our data support the hypothesis, revealing physical mechanisms for the increase of early-season freezing events with climate warming. The physical mechanisms should provide a general explanation for the topography-dependent pattern of tree species distribution and alpine treeline stability under climate warming in high mountainous regions like the Himalayas.

Justification of the CRIRSCO standards and JORC Code for mineral resources and reserves in high-mountain regions

The article discusses the CRIRSCO and JORC international reporting standards for the transition to the JORC Code in evaluation of mineral resources in the Kyrgyz Republic.

Accumulation of essential mineral and toxic trace elements in crops and soils of vegetable cropping systems in central highlands of Sri Lanka

AbstractVegetables are widely cultivated in high rainfall and mountainous regions in Sri Lanka with poor soil conservation practices. Accumulation of essential mineral and toxic trace elements in the soils and widely cultivated vegetables of this region are poorly understood. One hundred soil and vegetable (i.e. cabbage, carrot and potato) samples were collected at the time of harvest and analysed for element concentrations. Soils contained high concentrations of essential mineral (N, P, K, Cu, Zn and Mn) and toxic trace elements (As, Cd and Pb). When comparing edible parts, cabbage contained the highest concentrations of mineral and toxic trace elements, and potato contained the lowest. Irrespective of the crop, edible parts contained high concentrations of N, P, K (14–35, 2–6, 15–24 g/kg, respectively), and Cu, Zn, Mn (2.5–6.7, 11–30, 8–147 mg/kg, respectively). Vegetables also contained As, Cd and Pb (0.04–1, 0.02–0.15, 0.02–0.26 mg/kg, respectively), but did not exceed the maximum permissible limits. Irrespective of the crop, 36–64 kg N, 6–11 kg P and 35–45 kg K per ha were removed with the harvest. According to the current rate of vegetable consumption by Sri Lankans (i.e. 240 g fresh weight (FW) per day), per capita consumption of 0.05–0.2 mg Cu, 0.45–0.65 mg Zn and 0.5–2 mg Mn per day through these vegetables was observed, i.e. 5–23% Cu, 7.5–11% Zn and 22–87% Mn of the recommended daily intake. Vegetables grown in the region served as a key source of essential mineral elements. However, agronomic mitigation strategies are needed to improve soil health and sustainability of these cropping systems.

Cryoconites as biogeochemical markers of anthropogenic impact in high mountain regions: analysis of polyaromatic pollutants in soil-like bodies

The globalisation and omnidirectional character of anthropogenic processes has challenged scientists around the world to estimate the harmful effects of these processes on ecosystems and human health. Polycyclic aromatic hydrocarbons (PAHs) is one the most infamous group of contaminants, originated both from natural and anthropogenic processes. They could transport to high latitudes and altitudes through atmospheric long-distance transfer and further enter ecosystems of these vulnerable regions by deposition on terrestrial surfaces. An interesting object for tracking transboundary contamination processes in high mountain ecosystems is called cryoconite. Cryoconite, a dark-coloured supraglacial sediment which is abundant in polar and mountain environments, is considered as a storage of various pollutants, including PAHs. Thus, it may pose a risk for local human health and ecosystem through short-distance transfer. Studied cryoconite sediments were collected at the surface of Skhelda and Garabashi glaciers, Central Caucasus high-mountain region, as well as mudflow, moraine material and local soils at the Baksan Gorge in order to examine levels of their contamination. We analysed the content of 15 priority polyaromatic compounds from the US EPA list and used the method of calculation of PAHs isomer ratios with the purpose of identifying their source. To estimate their potential toxicity, Benzo[a]pyrene (BaP) equivalents were calculated. Maximum concentration was defined for NAP (84 ng×g-1), PHE (40 ng×g-1) and PYR (47 ng×g-1), with the minimum concentration for ANT (about 1 ng×g-1). The most polluted material is a cryoconite from Garabashi glacier because of local anthropogenic activities and long-distance transfer. High-molecular weight PAHs are dominated in PAHs composition of almost all samples. The most common sources of PAHs in studied materials are combustion processes and mixed pyrolytic/petrogenic origin. Toxicity levels of separate PAHs did not exceed the maximum permissible threshold concentrations values in most cases. However, the sum of PAHs in BaP equivalents exceed the threshold values in all samples, in some of them more than twice.

The &amp;lt;i&amp;gt;μ&amp;lt;/i&amp;gt;Dose system: determination of environmental dose rates by combined alpha and beta counting – performance tests and practical experiences

Abstract. The μDose system is a recently developed analytical instrument applying a combined α- and β-sensitive scintillation technique for determining the radioactivity arising from the decay chains of 235U, 238U and 232Th as well as from the decay of 40K. The device was designed to meet the particular requirements of trapped charge dating methods and allows the assessment of environmental (i.e. low) levels of natural radionuclides. The μDose system was developed as a piece of low-cost laboratory equipment, but a systematic test of its performance is still pending. For the first time, we present results from a comprehensive performance test based on an inter-laboratory comparison. We compare the results obtained with μDose measurements with those from thick source alpha counting (TSAC), inductively coupled plasma optical emission spectrometry (ICP-OES) and low-level high-resolution gamma spectrometry (HRGS) applied in five participating laboratories. In addition, the reproducibility and accuracy of μDose measurements were tested on certified reference materials distributed by the International Atomic Energy Agency (IAEA; RGU-1, RGTh-1 and RGK-1) and on two loess standards (Nussy and Volkegem) frequently used in trapped charge dating studies. We compare μDose-based results for a total of 47 sediment samples with results previously obtained for these materials by well-established methods of dose rate determination. The investigated natural samples cover a great variety of environments, including fluvial, aeolian, littoral, colluvial and (geo-)archaeological sites originating from high and low mountain regions as well as from lowlands in tropical areas, drylands and mid-latitude zones of Europe, Africa, Australia, Central Asia and the Americas. Our results suggest the μDose system's capability of assessing low-level radionuclide contents with very good accuracy and precision comparable to well-established dosimetry methods. Based on the results of our comparative study and with respect to the practical experiences gained so far, the μDose system appears to be a promising tool for trapped charge dating studies.

Morphological and habitat characteristics of Prasiola fluviatilis (Prasiolales, Trebouxiophyceae, Chlorophyta) from the Altai Mountains, Mongolia

This paper aims to confirm the report of Prasiola fluviatilis in Mongolian Altai and describe some previously undescribed morphological features such as a screw-shaped stipe anchored in the mucilage pad strongly adherent to the substrate, and aplanospores. Prasiola fluviatilis could be distributed occasionally in the high mountain regions and possibly be a valuable indicator of the glacial shifts caused by global warming in severely warming regions like Mongolia.

Influence of Mountain Conditions on Road Fuel Consumption (Example of the Republic of Tajikistan)

Most of the highways of the Republic of Tajikistan pass in mountainous and high-mountainous regions at an altitude of 1500-3500 m above sea level. They are characterized by steep passes (slope up to 10-12%), a large number of turns (15-18 pieces per 1 km of track), small turning radii (8-15 m) and poor condition of the roadway (holes, bumps, clogging with stones). Difficult driving conditions lead to increased fuel consumption. On the basis of experimental studies, a mathematical model has been developed that takes into account the influence of various factors on the track fuel consumption of a truck. The experiments were carried out on heavy mining dump trucks: KamAZ-52212, BelAZ-7540V, Howo-ZZ3257N3847N1 and Shacman-SX3256DR384 during the construction of the Rogun HPP in the Republic of Tajikistan.

НЕКОТОРЫЕ АСПЕКТЫ ОТНОСИТЕЛЬНОГО РИСКА СМЕРТИ ОТ ИНФАРКТА МИОКАРДА ЖЕНСКОГО НАСЕЛЕНИЯ РЕСПУБЛИКИ ДАГЕСТАН

The article analyzes the relative risk (RR) of death from myocardial infarction (MI) in women in the ecological zones of the Republic of Dagestan (RD). An epidemiological study of all female deaths from MI in RD in 2011–2020 was carried out taking into account their residence in cities and rural areas of various ecological zones. The analysis of the RR of mortality by altitude belts indicates that the foothills and mountains of RD are areas of increased risk of death from MI for the female population, while on the plains the same indicator is insignificantly lower. The highest mortality rate from MI among women was recorded in the south of the mountainous ecological zone (8.1 cases per 100,000 female population) with an RR of 1.3. Aim: analysis of the relative risk (RR) of death from myocardial infarction (MI) among women of ecological zones of the Republic of Dagestan (RD). Materials and methods: An epidemiological study of all female deaths from MI in RD in 2011–2020 was carried out taking into account their residence in cities and rural areas of various ecological zones. Results: An analysis of the RR of mortality in the high-altitude zones indicates that the foothills and mountains of the Republic of Dagestan are areas of increased risk of death from MI among female population. However, in the plain the same indicator is insignificantly lower. The highest mortality rate from MI among women was registered in the south of the mountain ecological zone (EZ) (9.1 cases per 100,000 female population) with RR 1.4. These data can be considered evidence of the effect on the risk of death from myocardial infarction among the female population from the southern mountainous areas with a sharply continental climate, characterized by high-altitude hypoxia, affecting the oxygen supply processes in the myocardium. Conclusion: The areas of increased RR of mortality from myocardial infarction among the female population of rural areas include the high-mountainous regions of the southern mountains of the Republic of Dagestan.

ՄԵԾ ՀԱՅՔԻ ԱՐՑԱԽ ԵՎ ՍՅՈՒՆԻՔ ԱՇԽԱՐՀՆԵՐԻ ԺԱՅՌԱՊԱՏԿԵՐՆԵՐԸ / THE PETROGLYPHS OF SYUNIK AND ARTSAKH PROVINCES OF GREAT ARMENIA

The rock carvings of Armenia are of great cognitive importance as a historical and cultural primary source of the pre-literate era, which reflects the deep past in a very pictorial way. These monuments, representing almost all the important spheres of the ancestors' life, have preserved and convey a peculiar picture of their mental activity. Rock art, which arose in Armenia since ancient times, existed as a means of human cognition and communication, carrying out the functions of expressing, accumulating and transmitting information and feelings, thus ensuring the connection of generations, the continuity of life experience, mentality and culture, preserving the wisdom and essence of the past. Armenian rock art is distinguished by a huge number of images, stylistic diversity and rich content, and occupies a special place in the cultural heritage of the Ancient World. In the regions adjacent to the Armenian Highland, ancient petroglyphs are rare, while on the Highlands their high density of distribution, thematic and typological richness is observed. On the territory of Armenia, petroglyphs available for direct study (in situ) have been concentrated in seven main high-mountainous regions: the mountain ranges of Geghama, Vardenis, Teqsar, Syunik, Zangezur, Karvachar and the slopes of Aragats. In the Republic of Artsakh, rock carvings are located in the following places: in Askeran district – on the outskirts of Shushi and near Tandzatap village; in Shahumyan district – on the slopes of Karvachar mountains Porak, Skhtorasar, Harsnakar, Yerakatar, Toli, Lyulpar, at the headwaters of Tartar and Aghavno rivers, on the banks of Tsalk, Sev, Mets and Pokr Al lakes, and west from Eghtsategh village; in Kashatagh district – on the northern slope of Ishkhanasar, near the shore of lake Sevlich. The petroglyphs of the mountains of Artsakh and Syunik are direct evidences that the monuments of rock art throughout the Armenian Highland form a holistic system, where the continuity of the anthropological and cultural picture is clearly traced in space (400.000 km2) and in time (hundreds of thousands of years). At present, a comprehensive study of this heritage based on the principles of Armenian studies and the creation of an electronic database due to modern methods of cartography is of primary importance.

Follow-up study about hydration parameters at moderate altitude: Measurements in healthy volunteers based on bio-electric impedance analysis (BIA)

During residence in high mountain regions, the human water hydration status changes and, from the height of ~ 3,000 m above sea level, is associated with the risk of mountain sickness. The present investigation assessed this phenomenon at moderate height (1,300–2,300 m above sea level) after a residence time of approximately one week by means of bioelectric impedance analysis (BIA). 132 volunteers, attendees of a sports medicine congress (78 men, 54 women), agreed to enter the study. All participants underwent BIA measurements initially and after one week’s time. Apart from the basic characteristics – resistance (resistor, R) and capacitor resistor (reactance, Xc) – derived characteristics such as whole body water (TBW), body cell mass (BCM) or extracellular cell mass (ECM) were of interest. Significant changes after the stay in moderate altitude were only verified with regard to hand resistance (R). As the resistance decreased in both men and women, tissue hydration was probably stimulated. In conclusion, the study showed that a 1-week stay at moderate altitude shows only a slight influence on the BIA parameters.

КОКОН ХАНДЫГЫНЫН МЕЗГИЛИНДЕГИ КЫРГЫЗДАРДЫН САЛТТУУ ЧАРБАЧЫЛЫГЫНЫН ѲНҮГҮШҮ

The article examines the economic life of the Kyrgyz people during the period of the Kokand Khanate. Cattle breeding is characterized as the main source of livelihood, the wealth and fame of each family was determined by the number of livestock. It was also noted that in the high-mountainous regions of Kyrgyzstan, livestock raising was in the first place, and agriculture in second. In different regions, agriculture is developed at different levels, depending on soil conditions. The economic importance of international trade routes passing through the territory of Kyrgyzstan increased, as well as the importance of trade routes for maintaining economic ties between the Central Asian khanates, Kyrgyzstan and East Turkestan.

National natural&amp;nbsp;heritage at risk: The Seven Rila Lakes

The area of the Seven Rila Lakes is situated in the North-West part of the Rila Mountain at an altitude between 2100 and 2500 m a.s.l. within the borders of Rila National Park. There are 140 glacial lakes in Rila Mountain but the area of the Seven Rila Lakes is the most visited and famous with its natural beauty and sacred significance. It is a valuable part of the national natural heritage. The popularity of this area grows constantly with the number of visitors from the country and abroad. This process leads to the deterioration of the natural conditions in the site. At the same time, it is not clear what is the effect of climate change on the environment in the lake&amp;rsquo;s area. There are many factors that contribute to the degradation of ecosystems in the protected area of the Seven Rila Lakes and pose risk to this valuable natural heritage. These factors are natural (mainly climate change-related), anthropogenic (associated with the excessive tourist pressures on the ecosystems in the protected area), and management (stemming from the ongoing conservation policy over the years). This study explores to what extent climate change may put at risk the ecosystems of Seven Rila Lakes. Mean monthly data from The European Center for Medium-Range Weather Forecasts (ECMWF) ERA5-Land reanalysis were used in this study. The resolution of these data is 0.1 x 0.1 (9 x 9 km) and their period is 1981-2020. Reanalysis data include air temperature, precipitation, evaporation, snow depth, etc. Based on data from various sources such as reanalysis data, in situ measurements, and statistical modeling, a scenario, based on current trends in different climatic elements, has been developed in order to project future changes and their impact on lake ecosystems. The results of the modelling of climate change show that in the coming decades an increase in temperature is expected in the high mountain regions of South-western Bulgaria and in particular in the Seven Rila Lakes area. This, combined with the ever-increasing flow of tourists, and high demand for the provided cultural ecosystem services, and insufficient management practices, put at risk the state of the lakes and their capacity to provide the same quality of cultural ecosystem services in the future, which attracts tourists in the area now. Recommendations have been made for the optimization of the management of the protected area in accordance with the observed trends.

Evidence of elevation-dependent warming from the Chinese Tian Shan

Abstract. The phenomenon in which the warming rate of air temperature is amplified with elevation is termed elevation-dependent warming (EDW). It has been clarified that EDW can accelerate the retreat of glaciers and melting of snow, which can have significant impacts on the regional ecological environment. Owing to the lack of high-density ground observations in high mountains, there is widespread controversy regarding the existence of EDW. Current evidence is mainly derived from typical high-mountain regions such as the Swiss Alps, the Colorado Rocky Mountains, the tropical Andes and the Tibetan Plateau–Himalayas. Rare evidence in other mountain ranges has been reported, especially in arid regions. In this study, EDW features (regional warming amplification and altitude warming amplification) in the Chinese Tian Shan (CTM) were detected using a unique high-resolution (1 km, 6-hourly) air temperature dataset (CTMD) from 1979 to 2016. The results showed that there were significant EDW signals at different altitudes on different timescales. The CTM showed significant regional warming amplification in spring, especially in March, and the warming trends were greater than those of continental China with respect to three temperatures (minimum temperature, mean temperature and maximum temperature). The significance values of EDW above different altitude thresholds are distinct for three temperatures in 12 months. The warming rate of the minimum temperature in winter showed a significant elevation dependence (p&lt;0.01), especially above 3000 m. The greatest altitudinal gradient in the warming rate of the maximum temperature was found above 4000 m in April. For the mean temperature, the warming rates in June and August showed prominent altitude warming amplification but with different significance above 4500 m. Within the CTM, the Tolm Mountains, the eastern part of the Borokoonu Mountains, the Bogda Mountains and the Balikun Mountains are representative regions that showed significant altitude warming amplification on different timescales. This new evidence could partly explain the accelerated melting of snow in the CTM, although the mechanisms remain to be explored.

Initial carbonate weathering is linked with vegetation development along a 127-year glacial retreat chronosequence in the subtropical high mountainous Hailuogou region (SW China)

AimsThe retreat of glaciers is exposing new terrains to primary plant succession around the globe. To improve the understanding of vegetation development along a glacier retreat chronosequence, we (i) evaluated a possible link between base metal (Ca, Mg, K, Na) supply and vegetation establishment, (ii) determined the rates of the establishment of soil and plant base metal stocks, and (iii) estimated the size of the main base metal fluxes.MethodsWe determined base metal stocks in the soil organic layer, the mineral topsoil (0–10 cm), and in leaves/needles, trunk, bark, branches and roots of the dominating shrub and tree species and estimated fluxes of atmospheric deposition, plant uptake and leaching losses along the 127-yr Hailuogou chronosequence.ResultsTotal ecosystem Ca and Mg stocks decreased along the chronosequence, while those of K and Na were unrelated with ecosystem age. Fortyfour and 30% of the initial stocks of Ca and Mg, respectively, were leached during the first 47 years, at rates of 130 ± 10.6 g m−2 year−1 Ca and 35 ± 3.1 g m−2 year−1 Mg. The organic layer accumulated at a mean rate of 288 g m−2 year−1 providing a bioavailable base metal stock, which was especially important for K cycling.ConclusionsWe suggest that the initial high Ca bioavailability because of a moderately alkaline soil pH and carbonate depletion in 47 years, together with the dissolution of easily-weatherable silicates providing enough Mg and K to the pioneer vegetation, contributed to the establishment of the mature forest in ca. 80 years.

Evaluating underlying causative factors for earthquake-induced landslides and landslide susceptibility mapping in Upper Indrawati Watershed, Nepal

The main objective of this study is to understand the overall impact of earthquake in upper Indrawati Watershed, located in the high mountainous region of Nepal. Hence, we have assessed the relationship between the co-seismic landslide and underlying causative factors as well as performed landslide susceptibility mapping (LSM) to identify the landslide susceptible zone in the study area. We assessed the landslides distribution in terms of density, number, and area within 85 classes of 13 causal factors including slope, aspect, elevation, formation, land cover, distance to road and river, soil type, total curvature, seismic intensity, topographic wetness index, distance to fault, and flow accumulation. The earthquake-induced landslide is clustered in Northern region of the study area, which is dominated by steep rocky slope, forested land, and low human density. Among the causal factors, 'slope' showed positive correlation for landslide occurrence. Increase in slope in the study area also escalates the landslide distribution, with highest density at 43%, landslide number at 4.34/km2, and landslide area abundance at 2.97% in a slope class (> 50°). We used logistic regression (LR) for LSM integrating with geographic information system. LR analysis depicts that land cover is the best predictor followed by slope and distance to fault with higher positive coefficient values. LSM was validated by assessing the correctly classified landslides under susceptibility categories using area under curve (AUC) and seed cell area index (SCAI). The LSM approach showed good accuracy with respective AUC values for success rate and prediction rate of 0.843 and 0.832. Similarly, the decreasing SCAI value from very low to very high susceptibility categories advise satisfactory accuracy of the LSM approach.

Testing the performance of ice thickness models to estimate the formation of potential future glacial lakes in Austria

AbstractThe emergence of glacial lakes is a significant consequence of global climate change in high mountain regions. Recent developments in ice thickness modelling combined with high‐resolution glacier surface data led to the generation of modelling approaches to simulate the ice‐free bedrock topography below current glaciers and to detect potential glacier bed overdeepenings (GBO) that may form into future lakes. We simulated the subglacial topography in the Austrian Alps using two different ice thickness models. Glaciers in the study area differ significantly from glaciers investigated in previous studies on potential future lakes because of their in general small size and location often restricted to cirques. The aim of this study is to estimate the number and location of potential future lakes in Austria. We tested the performance of ice thickness models for modelling of potential future lakes in an environment dominated by mountain glaciers that are under high stress of climate change. Modelling results are compared with lakes that evolved since the modelling periods and with data on subglacial topography derived from geophysical surveys. Results show significant differences in model performance concerning the total ice volume and the number of simulated GBOs. The number and total area of the modelled GBOs is overestimated, compared with the number of lakes that have evolved in the past. Most GBOs are simulated for valley type glaciers, even though most glaciers are mountain types. This does not match with the location of existing glacial lakes that are dominantly found in cirques. We ascertain that this modelling approach performs better on large valley type glaciers and less well on mountain glaciers. Intersecting the modelling runs indicates that up to 42 new lakes may form within 23 glaciers in Austria covering a total area of 2 km2.

Influence of water vapor and aerosols on downward longwave radiation in the high mountain region of Musala peak, Bulgaria

This study reveals the effect of aerosols and water vapor on downward longwave radiation in the high mountain region of Musala peak, Bulgaria. The investigated period is 01/01/2017 (Jan. 1st 2017) &amp;ndash; 30/09/2019 (Sep. 30th 2019). Statistical methods are the main tool for discovering the relationships between the different elements. The results indicate that air temperature is the leading factor for downward longwave radiation, specific humidity, and amount of aerosols in the air. That is why, in order to reveal the pure relationship between downward longwave radiation, specific humidity and amount of aerosols in the atmosphere, the air temperature was cleared from the data series. After this procedure, the results show that specific humidity has a significant influence on the downward longwave radiation flux, and an increase of 1% of the specific humidity results in an increase of about 12-15% in the values &amp;nbsp; of the downward longwave radiation. At air temperatures around 0&amp;ordm;C the influence of water vapor on the downward longwave flux is highest, which is due to the phase transitions of the water &amp;ndash; a process during which release/absorption of radiation in the longwave spectrum occurs. The amount of aerosols in the atmosphere also has a significant effect on this type of radiation, and an increase of 1% of the amount of aerosols in the air at air temperatures above &amp;ndash;5.5&amp;deg;C results in an increase of the downward longwave radiation of about 2-4%. The findings of this study show that coarser and opaque aerosol particles have a stronger effect on downward longwave radiation. In the area of Musala peak, as the air temperature rises, there is an increase in the amount of aerosols in the air, a decrease in their size, and a transition from transparent to opaque aerosols. The combination of these different tendencies causes the influence of aerosols on downward longwave radiation to be strongest in the middle temperature interval &amp;ndash; air temperatures between &amp;ndash;5.5&amp;deg;C and +5.5&amp;deg;C. Due to the increased total amount of aerosols and increased amount of opaque aerosols, their influence on downward longwave radiation is significant also at air temperatures above 5.5&amp;deg;C.