共检索到 8

Rapid Arctic warming is expected to result in widespread permafrost degradation. However, observations show that site-specific conditions (vegetation and soils) may offset the reaction of permafrost to climate change. This paper summarizes 43 years of interannual seasonal thaw observations from tundra landscapes surrounding the Marre-Sale on the west coast of the Yamal Peninsula, northwest Siberia. This robust dataset includes landscape-specific climate, active layer thickness, soil moisture, and vegetation observations at multiple scales. Long-term trends from these hierarchically scaled observations indicate that drained landscapes exhibit the most pronounced responses to changing climatic conditions, while moist and wet tundra landscapes exhibit decreasing active layer thickness, and river floodplain landscapes do not show changes in the active layer. The slow increase in seasonal thaw depth despite significant warming observed over the last four decades on the Yamal Peninsula can be explained by thickening moss covers and ground surface subsidence as the transient layer (ice-rich upper permafrost soil horizon) thaws and compacts. The uneven proliferation of specific vegetation communities, primarily mosses, is significantly contributing to spatial variability observed in active layer dynamics. Based on these findings, we recommend that regional permafrost assessments employ a mean landscape-scale active layer thickness that weights the proportions of different landscape types.

2023-04-29 Web of Science

As one of the best indicators of the periglacial environment, ice-wedge polygons (IWPs) are important for arctic landscapes, hydrology, engineering, and ecosystems. Thus, a better understanding of the spatiotemporal dynamics and evolution of IWPs is key to evaluating the hydrothermal state and carbon budgets of the arctic permafrost environment. In this paper, the dynamics of ground surface deformation (GSD) in IWP zones (2018-2019) and their influencing factors over the last 20 years in Saskylakh, northwestern Yakutia, Russia were investigated using the Interferometric Synthetic Aperture Radar (InSAR) and Google Earth Engine (GEE). The results show an annual ground surface deformation rate (AGSDR) in Saskylakh at -49.73 to 45.97 mm/a during the period from 1 June 2018 to 3 May 2019. All the selected GSD regions indicate that the relationship between GSD and land surface temperature (LST) is positive (upheaving) for regions with larger AGSDR, and negative (subsidence) for regions with lower AGSDR. The most drastic deformation was observed at the Aeroport regions with GSDs rates of -37.06 mm/a at tower and 35.45 mm/a at runway. The GSDs are negatively correlated with the LST of most low-centered polygons (LCPs) and high-centered polygons (HCPs). Specifically, the higher the vegetation cover, the higher the LST and the thicker the active layer. An evident permafrost degradation has been observed in Saskylakh as reflected in higher ground temperatures, lusher vegetation, greater active layer thickness, and fluctuant numbers and areal extents of thermokarst lakes and ponds.

2023-03-01 Web of Science

Arctic zone of the Russian Federation (AZRF) is the region of intensive economic development. In this regard, it is critical to give an adequate assessment of natural factors that may have a negative impact on the growing technological infrastructure. Rapid climate change effects show a significant influence on this activity, including the railway network development. Hence, the decision-making community requires relevant information on climatic variations that can put at hazard the construction and operation of railway facilities. This paper presents the analysis of climatic changes within the region of Central and Western Russian Arctic in 1980-2021. It was performed using the new electronic Atlas of climatic variations in main hydrometeorological parameters, created for the Russian Railways in 2023. This geoinformatic product includes about 400 digital maps reflecting the variability of seven climatic parameters over more than four decades within the studied region. These parameters are air temperature, total precipitation, wind speed, soil temperature, soil moisture content, air humidity, and snow cover thickness. The analysis of climatic maps and their comparison between selected periods showed spatial and temporal heterogeneity of climatic variations in this region. This justifies the feasibility of further research using additional analytical instruments, such as Hovm & ouml;ller diagrams, time series graphs, etc. The implementation of advanced geoinformatic products in the practice of the Russian Railways will facilitate sustainable development of its infrastructure in rapidly altering climatic conditions.

2023-01-01 Web of Science

This is an attempt to predict the potential economic impacts on public infrastructure upon degrading permafrost which is losing its bearing capacity. Climate change-related increases in costs (economic losses or damage) are estimated for several climate futures by 2050 separately for 39 municipalities located in the Russian Arctic permafrost domain. The hypothetical changes in mean annual ground temperature are inferred from air and ground temperature trends and monitoring data, with reference to forecasts of the Climate Center of the Russian Meteorological Service (Roshydromet) and climate change scenarios (representative concentration pathways RCP2.6, RCP4.5, and RCP8.5). The calculations were performed for twelve possible cases with different air ground temperature assumptions, with regard to the difference between the ground and air mean annual temperatures. This difference, or temperature shifts, due to radiation, snow, vegetation, and atmospheric precipitation effects, was estimated either by means of calculations proceeding from possible changes of climate variables or by summation of known values reported from different Arctic areas. The economic losses were evaluated as maximum and minimum values at extreme values of permafrost parameters, separately for each case. The buildings and facilities on permafrost were assumed to have pile foundations with friction piles. The permafrost thaw impact was meant as the loss of the soil capacity to bear the support structures for the infrastructure leading to deformation and failure. The impact was considered significant if the change exceeded the safety margin according to the Russian Building Code. The greatest damage is expected to housing stock and buildings and structures of main economic sectors. The monetary value of the residential infrastructure was estimated using a specially compiled inventory database including address, age, and surface area of 23.900 houses in 39 selected Russian Arctic municipalities over a total area of 44.600 km(2). The estimation of fixed assets stemmed from the assumption that their monetary value is proportional to the gross output in the respective economic sector, which, in its turn, correlates with the payroll total corrected for mean industry coefficients for different regions of Russia. The potential damage may reach up to US$ 132 billion (total) and similar to US$ 15 billion for residential infrastructure alone, which generally agrees with other estimates.

2022-05-01 Web of Science

The Global Climate Observing System and Global Terrestrial Observing Network have identified permafrost as an 'Essential Climate Variable,' for which ground temperature and active layer dynamics are key variables. This work presents long-term climate, and permafrost monitoring data at seven sites representative of diverse climatic and environmental conditions in the western Russian Arctic. The region of interest is experiencing some of the highest rates of permafrost degradation globally. Since 1970, mean annual air temperatures and precipitation have increased at rates from 0.05 to 0.07 degrees C yr(-1) and 1 to 3 mm yr(-1) respectively. In response to changing climate, all seven sites examined show evidence of rapid permafrost degradation. Mean annual ground temperatures increases from 0.03 to 0.06 degrees C yr(-1) at 10-12 m depth were observed in continuous permafrost zone. The permafrost table at all sites has lowered, up to 8 m in the discontinuous permafrost zone. Three stages of permafrost degradation are characterized for the western Russian Arctic based on the observations reported.

2020-04-01 Web of Science

Forty soil and lichen samples and sixteen soil horizon samples were collected in the mining and surrounding areas of the Yamal-Nenets autonomous region (Russian Arctic). The positive matrix factorization (PMF) model was used for the source identification of PAHs. The results of the source identification showed that the mining activity was the major source of PAHs in the area, and that the mining influenced the surrounding natural area. The 5+6-ring PAHs were most abundant in the mining area. The lichen/soil (LAS) results showed that 2+3-ring and 4-ring PAHs could be transported by air and accumulated more in lichens than in the soil, while 5+6-ring PAHs accumulated more in the soil. Strong relationships between the quotient of soil/lichen (Q(SL)) and Log K-OA and Log P-L and between the quotient of lichen/histic horizon soil and K-OW were observed. In addition, hydrogeological conditions influenced the downward transport of PAHs. Particularly surprising is the discovery of the high levels of 5 + 6 rings in the permafrost table (the bottom of the active layer). One hypothesis is given that the global climate change may lead to further depth of active layer so that PAHs may migrate to the deeper permafrost. In the impact area of mining activities, the soil inventory for 5+6-ring PAHs was estimated at 0.14 +/- 0.017 tons on average. (C) 2019 Elsevier Ltd. All rights reserved.

2019-12-01 Web of Science

One of the most significant climate change impacts on arctic urban landscapes is the warming and degradation of permafrost, which negatively affects the structural integrity of infrastructure. We estimate potential changes in stability of Russian urban infrastructure built on permafrost in response to the projected climatic changes provided by six preselected General Circulation Models (GCMs) participated in the most recent Climate Model Inter-comparison Project (CMIP5). The analysis was conducted for the entire extent of the Russian permafrost-affected area. According to our analysis a significant (at least 25%) climate-induced reduction in the urban infrastructure stability throughout the Russian permafrost region should be expected by the mid-21st century. However, the high uncertainty, resulting from the GCM-produced climate projections, prohibits definitive conclusion about the rate and magnitude of potential climate impacts on permafrost infrastructure. Results presented in this paper can serve as guidelines for developing adequate adaptation and mitigation strategy for Russian northern cities.

2017-01-01 Web of Science

Role of changing climatic conditions on permafrost degradation and hydrology was investigated in the transition zone between the tundra and forest ecotones at the boundary of continuous and discontinuous permafrost of the lower Yenisei River. Three watersheds of various sizes were chosen to represent the characteristics of the regional landscape conditions. Samples of river flow, precipitation, snow cover, and permafrost ground ice were collected over the watersheds to determine isotopic composition of potential sources of water in a river flow over a two year period. Increases in air temperature over the last forty years have resulted in permafrost degradation and a decrease in the seasonal frost which is evident from soil temperature measurements, permafrost and active-layer monitoring, and analysis of satellite imagery. The lowering of the permafrost table has led to an increased storage capacity of permafrost affected soils and a higher contribution of ground water to river discharge during winter months. A progressive decrease in the thickness of the layer of seasonal freezing allows more water storage and pathways for water during the winter low period making winter discharge dependent on the timing and amount of late summer precipitation. There is a substantial seasonal variability of stable isotopic composition of river flow. Spring flooding corresponds to the isotopic composition of snow cover prior to the snowmelt. Isotopic composition of river flow during the summer period follows the variability of precipitation in smaller creeks, while the water flow of larger watersheds is influenced by the secondary evaporation of water temporarily stored in thermokarst lakes and bogs. Late summer precipitation determines the isotopic composition of texture ice within the active layer in tundra landscapes and the seasonal freezing layer in forested landscapes as well as the composition of the water flow during winter months.

2015-09-01 Web of Science
  • 首页
  • 1
  • 末页
  • 跳转
当前展示1-8条  共8条,1页