scholarly journals Mobilization of Geochemical Elements to Surface Water in the Active Layer of Permafrost in the Russian Arctic

2021 ◽  
Vol 57 (1) ◽  
Author(s):  
Xiaowen Ji ◽  
Evgeny Abakumov ◽  
Vyacheslav Polyakov ◽  
Xianchuan Xie
Keyword(s):  
Surface Water ◽  
Active Layer ◽  
Russian Arctic ◽  
Geochemical Elements

scholarly journals Methane Content and Emission in the Permafrost Landscapes of Western Yamal, Russian Arctic

Geosciences ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 412
Author(s):  
Gleb E. Oblogov ◽  
Alexander A. Vasiliev ◽  
Irina D. Streletskaya ◽  
Natalia A. Zadorozhnaya ◽  
Anna O. Kuznetsova ◽  
...  
Keyword(s):  
Active Layer ◽  
Methane Content ◽  
Yamal Peninsula ◽  
Peat Bogs ◽  
Western Coast ◽  
Permafrost Degradation ◽  
Russian Arctic ◽  
Landscape Map ◽  
The Yamal Peninsula ◽  
Lake Basins

We present the results of studies of the methane content in soils of the active layer and underlying permafrost, as well as data on the emission of methane into the atmosphere in the dominant landscapes of typical tundra of the western coast of the Yamal Peninsula. A detailed landscape map of the study area was compiled, the dominant types of landscapes were determined, and vegetation cover was described. We determined that a high methane content is characteristic of the wet landscapes: peat bogs within the floodplains, water tracks, and lake basins. Average values of the methane content in the active layer for such landscapes varied from 2.4 to 3.5 mL (CH4)/kg, with a maximum of 9.0 mL (CH4)/kg. The distribution of methane in studied sections is characterized by an increase in its concentration with depth. This confirms the diffuse mechanism of methane transport in the active layer and emission of methane into the atmosphere. The transition zone of the upper permafrost contains 2.5–5-times more methane than the active layer and may become a significant source of methane during the anticipated permafrost degradation. Significant fluxes of methane into the atmosphere of 2.6 mg (CH4) * m−2 * h−1 are characteristic of the flooded landscapes of peat bogs, water tracks, and lake basins, which occupy approximately 45% of the typical tundra area.

Modeling recent permafrost thaw and associated hydrological changes in an endorheic Tibetan watershed

2021 ◽  
Author(s):  
Walter Immerzeel ◽  
Léo Martin ◽  
Fanny Brun ◽  
Sebastian Westermann ◽  
Joel Fiddes ◽  
...  
Keyword(s):  
Surface Water ◽  
Active Layer ◽  
Large Scale ◽  
Meteorological Data ◽  
Significant Proportion ◽  
Heat Fluxes ◽  
Phase Changes ◽  
Tibet Plateau ◽  
Permafrost Thaw ◽  
Scientific Challenge

<p>Permafrost has a crucial influence on sub-surface water flow and thus on the hydrology of catchments. Its thawing drives the release of frozen water and a transition from surface-water-dominated systems to groundwater-dominated systems. In the context of global warming, these hydrological modifications are of critical importance for extensive headwater regions such as the Qinghai-Tibet Plateau (QTP) and the Himalayas. Permafrost covers a significant proportion of these regions (40% of the QTP), which are major water towers of the world. Therefore, improving our understanding and ability to quantify these changes are a key scientific challenge.</p><p>Many watersheds of the QTP have seen their hydrologic budget modified over the last decades as evidenced by strong lake level variations observed in endorheic basins. Yet, the possible contribution of permafrost thaw to these variations has not been assessed. The Paiku basin (central Himalayas, southern TP) finds itself in a similar situation. The Paiku lake at the lowest point of this endorheic basin has exhibited important level decreases since the 70’s and thus offers the possibility to test the potential role of permafrost thaw on these hydrologic changes. We present permafrost simulations at the scale of the basin over the last four decades that reproduce its degradation as result of regional climatic change. We use the Cryogrid model to simulate the surface energy balance, snow pack dynamics and the ground thermal regime while accounting for the phase changes and the soil water budget. Because the surface radiative, sensitive and latent heat fluxes in alpine environments are strongly dependent on the physiography the model is forced with distributed downscaled forcing data produced with the TOPOSCALE model to account for this spatial variability. Simulated surface conditions are evaluated against meteorological data acquired within the basin and remotely sensed surface temperatures.</p><p>The simulations show that, contrary to large scale estimates of permafrost occurrence probability, an important part of the basin is underlaid by permafrost. During the simulated period, permafrost distribution and active layer exhibit limited variations (active layer deepening neighboring 10 cm) yet deeper ground temperatures (7-8 m) show a warming close to 0.8 degree (0.2 degree per decade). These first results tend to indicate a limited contribution of permafrost to the catchment hydrology over the last decades, a trend that could be significantly modified in the future if the simulated warming rates persist and lead to increased permafrost thawing.</p>

scholarly journals Contrasting extreme runoff events in areas of continuous permafrost, Arctic Alaska

2008 ◽  
Vol 39 (4) ◽  
pp. 287-298 ◽  
Author(s):  
Douglas L. Kane ◽  
Larry D. Hinzman ◽  
Robert E. Gieck ◽  
James P. McNamara ◽  
Emily K. Youcha ◽  
...  
Keyword(s):  
Surface Water ◽  
Active Layer ◽  
Coastal Plain ◽  
The Arctic ◽  
Near Surface ◽  
Extreme Flows ◽  
Continuous Permafrost ◽  
Drought Conditions ◽  
Snowmelt Flood ◽  
Kuparuk River

Spring snowmelt floods in the Arctic are common and can be expected every year, mainly because of the extensive snow cover that ablates relatively quickly. However, documentation of extreme flows (both low and high) in the Arctic is lacking in part because extreme flows are relatively rare and gauging sites are very sparse, with most of short duration. In the nested Kuparuk River research watersheds on the North Slope of Alaska, two large summer floods have been observed (July 1999 and August 2002) in the headwaters; these high flows are contrasted to the low flows (drought conditions) observed in the summers of 2005 and 2007. It is clear that the continuous permafrost and the limited near-surface storage in the shallow active layer are responsible for both the high and low flow responses. Or, stated another way, the active layer is a poor buffer to both floods and droughts. When contrasting summer floods with snowmelt floods, it is clear from flood frequency analyses that the smaller, high-gradient headwater basins will be dominated by summer floods while those watersheds draining the low gradient coastal plain will be dominated by snowmelt floods. The two summer floods in the headwaters had flows that were three to four times greater than the largest measured snowmelt flood, while on the coastal plain the 2002 summer storm for the whole of the Kuparuk River only produced the maximum summer runoff of record that was about 1/4 of the maximum snowmelt flood. So, on the coastal plain and even for the Greater Kuparuk River that drains across the coastal plain, snowmelt floods dominate. Drought conditions prevail in summers when the limited surface water storage in the active layer and surface water bodies is depleted because evapotranspiration exceeds precipitation.

scholarly journals Estimating interaction between surface water and groundwater in a permafrost region using heat tracing methods

2017 ◽  
Author(s):  
Tanguang Gao ◽  
Jie Liu ◽  
Tingjun Zhang ◽  
Yuantao Hu ◽  
Jianguo Shang ◽  
...  
Keyword(s):  
Surface Water ◽  
Active Layer ◽  
Spatial Scales ◽  
Permafrost Region ◽  
Conductive Heat ◽  
Distributed Temperature Sensing ◽  
Northern Tibetan Plateau ◽  
Surface Water And Groundwater ◽  
Heat Transport Equation ◽  
Permafrost Regions

Abstract. Understanding the interactions between groundwater and surface water in permafrost regions is essential to the understanding of flood frequencies and river water quality of high latitude/altitude basins. The application of heat tracing methods, based on oscillating streambed temperature signals, is a promising geophysical method for identifying and quantifying the groundwater and surface water interactions. Analytical analysis based on one-dimensional convective-conductive heat transport equation combined with the fiber-optic distributed temperature sensing measurements were applied on a streambed of a mountainous permafrost region in the Yeniugou basin of northern Tibetan Plateau. The results indicated that low connectivity between the stream and groundwater in permafrost and active layer. The interaction between surface water and groundwater increased with thawing of the active layer. This study demonstrates that heat tracing method can be applied to study surface water-groundwater interactions over temporal and spatial scales in permafrost regions.

scholarly journals The Laptev Sea flaw polynya, Russian Arctic: effects on the mesoscale hydrography

2001 ◽  
Vol 33 ◽  
pp. 373-376 ◽  
Author(s):  
I. Dmitrenko ◽  
J.A. Hölemann ◽  
K. Tyshko ◽  
V. Churun ◽  
S. Kirillov ◽  
...  
Keyword(s):  
Surface Water ◽  
Water Layer ◽  
Circulation System ◽  
Laptev Sea ◽  
Russian Arctic ◽  
Surface Water Salinity ◽  
Salinity Increase ◽  
Vertical Density ◽  
Ice Production ◽  
The Laptev Sea

AbstractA detailed analysis of hydrographic data from a period of 20 years (1980−99) has shown that the persistent presence of a flaw polynya influences mesoscale hydrography of the Laptev Sea, Russian Arctic. Based on these data, the interannual variability of surface water salinity within the polynya has been estimated. As the salinity increase in the surface water layer is mainly caused by the formation of new ice within the polynya, the average ice-production rate of the polynya was calculated. The results indicate an ice production of 3−4 m per season. A further aim of this study was to calculate the probability that the convective mixing in the polynya penetrates to the sea-floor. It is demonstrated that the probability is maximal in the flaw-polynya area, but does not exceed 20% in the eastern and 70% in the western part of the polynya as a result of strong vertical density stratification from river runoff, especially in the eastern Laptev Sea. Additional studies of water circulation in the marginal zone of the flaw polynya were carried out during field observations in April-May 1999. On the basis of conductivity-temperature-depth and current measurements we deduce that high current velocities (62 cm s-1) recorded in surface waters near the fast-ice edge are caused by a convectively driven circulation system under the polynya. Our measurements indicate that these high-velocity currents are part of a cellular circulation, which results from the rejection of brine during intensive ice formation in the polynya. The observed azimuthal alignment of the crystalline structure of sea ice is also, most probably, the consequence of this quasi-stationary cellular circulation.

Slope hydrology and permafrost: The effect of snowmelt N transport on downslope ecosystem

2020 ◽  
Author(s):  
Laura Helene Rasmussen ◽  
Per Ambus ◽  
Wenxin Zhang ◽  
Per Erik Jansson ◽  
Anders Michelsen ◽  
...  
Keyword(s):  
Surface Water ◽  
Active Layer ◽  
Water Movement ◽  
Ecosystem Respiration ◽  
N Uptake ◽  
Growing Season ◽  
Potential Effect ◽  
Near Surface ◽  
Vegetation Growth ◽  
N Input

<p>In the permafrost-affected landscape, surface and near-surface water movement links areas of higher elevation with lowlands and surface water bodies. Water supply is dominated by snow melt and is thus highly seasonal, as most water moves on the frozen surface in spring, passing only a thin layer of thawed soil. Soluble nutrients mobilized by soil thaw may thus be transported laterally from upslope to downslope ecosystems, which in nutrient-limited cold ecosystems may affect vegetation, ecosystem respiration and surface-atmosphere interaction. In a nitrogen (N) limited ecosystem, however, released inorganic N may in reality not travel far downslope. <br>This study quantifies the potential effect of the snowmelt water nutrient transport by tracing dissolved N in meltwater moving downslope on the frozen surface in a W Greenlandic slope with a snow fan supplying meltwater throughout most of the summer. We use the stable isotopes <sup>15</sup>N and D applied simultaneously on top of the frozen surface upslope in a combined solution to investigate the behavior of water and dissolved N flow patterns. We further address the effect of season by tracing N supplied in the early thaw season (30 cm to the frozen surface) and in the late thaw season (90 cm to the frozen surface). Monitoring the slope in detail, we then use the numerical coupled heat-and-mass transfer Coup model to simulate the biotics and abiotics of the receiving ecosystem and study the importance of the lateral N input and the effect of increased N transport in a warmer future.  <br>About 50 % of the N tracer was retained in the ecosystem immediately below injection in the early growing season (30 cm active layer), whereas about 35 % was retained in the later growing season (90 cm active layer). Most of the applied <sup>15</sup>N was rapidly immobilized by microbes and into the bulk soil, whereas only a few percentages was taken up by the vegetation. D recovery seemed to follow the pattern of microbial N uptake, suggesting that N and D moved physically from the frozen surface and to the immediate subsoil together.</p><p>Modelling the ecosystem based on measured N and C pool sizes, meteorology, soil temperature and –moisture revealed a large N constrain on vegetation growth. The current observed vegetation could not be explained with the measured pools alone, suggesting an “invisible” source of N to support the observed vegetation. We conclude that a substantial fraction of lateral N input is transported further downslope, but that increases in N release and transport might not affect vegetation immediately, as most supplied N ends in the soil pool. Vegetation in the receiving ecosystem relies on an external N source, which could be dissolved N transported by snowmelt water on the frozen surface. Snowmelt redistribution of N in the landscape may thus be a factor to account for when studying N cycling in a spatial context.</p>

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