| 1. |
- Ala-aho, P., et al.
(author)
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Permafrost and lakes control river isotope composition across a boreal Arctic transect in the Western Siberian lowlands
- 2018
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In: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 13:3, s. =20-=20
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Journal article (peer-reviewed)abstract
- The Western Siberian Lowlands (WSL) store large quantities of organic carbon that will be exposed and mobilized by the thawing of permafrost. The fate of mobilized carbon, however, is not well understood, partly because of inadequate knowledge of hydrological controls in the region which has a vast low-relief surface area, extensive lake and wetland coverage and gradually increasing permafrost influence. We used stable water isotopes to improve our understanding of dominant landscape controls on the hydrology of the WSL. We sampled rivers along a 1700 km South-North transect from permafrost-free to continuous permafrost repeatedly over three years, and derived isotope proxies for catchment hydrological responsiveness and connectivity. We found correlations between the isotope proxies and catchment characteristics, suggesting that lakes and wetlands are intimately connected to rivers, and that permafrost increases the responsiveness of the catchment to rainfall and snowmelt events, reducing catchment mean transit times. Our work provides rare isotope-based field evidence that permafrost and lakes/wetlands influence hydrological pathways across a wide range of spatial scales (10-105 km2) and permafrost coverage (0%-70%). This has important implications, because both permafrost extent and lake/wetland coverage are affected by permafrost thaw in the changing climate. Changes in these hydrological landscape controls are likely to alter carbon export and emission via inland waters, which may be of global significance.
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| 2. |
- Ala-aho, P., et al.
(author)
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Using stable isotopes to assess surface water source dynamics and hydrological connectivity in a high-latitude wetland and permafrost influenced landscape
- 2018
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In: Journal of Hydrology. - : Elsevier. - 0022-1694 .- 1879-2707. ; 556, s. 279-293
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Journal article (peer-reviewed)abstract
- Climate change is expected to alter hydrological and biogeochemical processes in high-latitude inland waters. A critical question for understanding contemporary and future responses to environmental change is how the spatio-temporal dynamics of runoff generation processes will be affected. We sampled stable water isotopes in soils, lakes and rivers on an unprecedented spatio-temporal scale along a 1700 km transect over three years in the Western Siberia Lowlands. Our findings suggest that snowmelt mixes with, and displaces, large volumes of water stored in the organic soils and lakes to generate runoff during the thaw season. Furthermore, we saw a persistent hydrological connection between water bodies and the landscape across permafrost regions. Our findings help to bridge the understanding between small and large scale hydrological studies in high-latitude systems. These isotope data provide a means to conceptualise hydrological connectivity in permafrost and wetland influenced regions, which is needed for an improved understanding of future biogeochemical changes.
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| 3. |
- Karlsson, Jan, 1974-, et al.
(author)
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Carbon emission from Western Siberian inland waters
- 2021
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Journal article (peer-reviewed)abstract
- High-latitude regions play a key role in the carbon (C) cycle and climate system. An important question is the degree of mobilization and atmospheric release of vast soil C stocks, partly stored in permafrost, with amplified warming of these regions. A fraction of this C is exported to inland waters and emitted to the atmosphere, yet these losses are poorly constrained and seldom accounted for in assessments of high-latitude C balances. This is particularly relevant for Western Siberia, with its extensive peatland C stocks, which can be strongly sensitive to the ongoing changes in climate. Here we quantify C emission from inland waters, including the Ob’ River (Arctic’s largest watershed), across all permafrost zones of Western Siberia. We show that the inland water C emission is high (0.08–0.10 Pg C yr−1) and of major significance in the regional C cycle, largely exceeding (7–9 times) C export to the Arctic Ocean and reaching nearly half (35–50%) of the region’s land C uptake. This important role of C emission from inland waters highlights the need for coupled land–water studies to understand the contemporary C cycle and its response to warming.
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| 4. |
- Krickov, Ivan V., et al.
(author)
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Sizable carbon emission from the floodplain of Ob River
- 2021
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In: Ecological Indicators. - : Elsevier. - 1470-160X .- 1872-7034. ; 131
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Journal article (peer-reviewed)abstract
- The Ob River floodplain is the second largest floodplain in the world. Despite its vast area, estimates of carbon (C) emissions from the Ob River floodplain are largely absent. Here we present seasonal C emission and water area extent from the main channel and the floodplain along a ~4 km reach in the boreal zone of the Ob River. We found strong seasonality in water area extent of the Ob main channel (~1.8 km2) and floodplain (~3 km2) with water covering 34% of land during flood and subsequently declining to ~16% and ~14% during summer and autumn baseflow, respectively. The C emissions also varied seasonally over the open water period, ranging from −0.1 to 0.6 g C m−2 d−1 for the Ob main channel and from 0 to 9 g C m−2 d−1 for the floodplain. The dissolved organic carbon positively affected CO2 concentrations and fluxes in the floodplain during all seasons, whereas pH and oxygen concentration negatively impacted CO2 concentrations and fluxes. Some nutrients (ammonia and phosphate) positively correlated with CO2 and CH4 concentrations in summer. The total C emission from the study reach (1.8 km2 main channel, 3 km2 floodplain) during moderate flooding was 236 ± 51 tons C yr−1 (>99% CO2, <1% CH4) with the floodplain accounting for ~65%. The contribution of the floodplain to the net river C evasion may be even greater during years of high flooding and in northern regions of the Ob River basin, where floodplain soils are more C-rich and are underlain by permafrost, and in years with more extensive flooding.
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| 5. |
- Serikova, Svetlana, 1989-, et al.
(author)
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Carbon emission from the boreal floodplain of Ob’ River
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Other publication (other academic/artistic)abstract
- The Ob’ River floodplain is the second largest floodplain in the world. Despite its vast area, estimates of carbon (C) emissions from the Ob’ River floodplain are largely absent. Here we present seasonal C emission and water area extent from the main channel and the floodplain along a ~4 km reach in the boreal zone of the Ob’ River. We find strong seasonality in water area extent of the Ob’ main channel (~1.8 km2) and floodplain (~3 km2) with water covering 34% of land during flood and subsequently declining to ~16 and 14% during summer and autumn baseflow, respectively. The C emissions also showed seasonal differences over the open water period ranging from 4.66 to -4.25 g C m-2 d-1 for the Ob’ main channel and from 0.03 to 1.42 g C m-2 d-1 for the floodplain. The total annual C emission from the study reach was ~940 ± 744 t C yr-1 with the floodplain accounting for ~16%. The contribution of the floodplain to the net river C evasion can be even greater in northern regions of the Ob’ River basin, where floodplain soils are more C-rich and are underlain by permafrost, and in years with more extensive flooding.
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| 6. |
- Serikova, Svetlana, 1989-, et al.
(author)
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Carbon emission from Western Siberian Inland Waters
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Other publication (other academic/artistic)abstract
- Western Siberia, with large carbon (C) stocks stored in permafrost, is a key region in the global C cycle. This region contains numerous rivers and lakes, including Arctic’s largest watershed – the Ob’ River, yet the role of inland waters in the regional C cycle is unknown. Here we quantify C emission from Western Siberian inland waters to ~0.1 ± 0.01 Pg C yr-1. The C emission exceeds region’s C export to the Arctic ocean by ~9-fold suggesting that any increase in region’s terrestrial C export will be largely evaded through inland waters and highlighting the need to account for coupled land-water C cycle to understand its response to warming.
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| 7. |
- Serikova, Svetlana, 1989-
(author)
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Carbon Emissions from Western Siberian Inland Waters
- 2019
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Doctoral thesis (other academic/artistic)abstract
- Inland waters (i.e. rivers, streams, lakes, ponds) emit carbon (C) into the atmosphere. The magnitude of global inland water C emission has been estimated to equal the global ocean C sink, thus making inland waters an important component of the global C cycle. Yet, the data used in estimating the magnitude of global inland water C emission lacks measurements of inland water C emissions from permafrost-affected regions in general and from Russia in particular, despite permafrost covering ~25% of the Northern Hemisphere and ~65% of Russia. This lack of data questions the accuracy of the current estimate of global inland water C emission and its predictive power in assessing changes in the global C cycle following permafrost thaw.In this thesis, we conducted detailed measurements of river and lake C emissions across ~1000 km permafrost gradient of Western Siberia (from permafrost-free to continuous permafrost zone) and assessed the magnitude of the total C emission from Western Siberian inland waters. We found that river and lake C emissions varied across the permafrost gradient with river C emissions being greatest in areas where permafrost is actively degrading, and lake C emissions being greatest in areas where permafrost is still intact. We also found that river and lake C emissions are likely driven by different factors with river C emissions being mainly controlled by temperature and hydrological conditions, whereas lake C emissions by sediment respiration and availability of recently thawed organic C. Further, we estimated the total C emission from Western Siberian inland waters to be greater than previously thought and exceeding the C export from this region to the Arctic Ocean. Such finding implies that a major part of the terrestrially-derived C is lost in Western Siberian inland waters, making this region a hotspot for inland water C emission following permafrost thaw. We also showed that apart from C emissions measurements across different inland water types and across the landscape, estimates of inland water surface areas are needed for accurate assessments of the total inland water C emission of any given region. Particularly, water surface areas of streams and ponds as well as inundated floodplains, especially in years of extreme flood events, are important for quantifying the total inland water C emission. Overall, this thesis presents new data related to C emissions from rivers and lakes in an area that undergoes rapid permafrost thaw, and urges to account for all inland water types and their respective water surface areas when attempting to achieve unbiased estimates of the inland water contribution to the atmospheric C budget.
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| 8. |
- Serikova, Svetlana, et al.
(author)
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High carbon emissions from thermokarst lakes of Western Siberia
- 2019
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In: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 10
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Journal article (peer-reviewed)abstract
- The Western Siberia Lowland (WSL), the world's largest permafrost peatland, is of importance for understanding the high-latitude carbon (C) cycle and its response to climate change. Warming temperatures increase permafrost thaw and production of greenhouse gases. Also, permafrost thaw leads to the formation of lakes which are hotspots for atmospheric C emissions. Although lakes occupy similar to 6% of WSL, lake C emissions from WSL remain poorly quantified. Here we show high C emissions from lakes across all permafrost zones of WSL. The C emissions were especially high in shoulder seasons and in colder permafrost-rich regions. The total C emission from permafrost-affected lakes of WSL equals similar to 12 +/- 2.6 Tg C yr(-1) and is 2-times greater than region's C export to the Arctic coast. The results show that C emission from WSL lakes is a significant component in the high-latitude C cycle, but also suggest that C emission may decrease with warming.
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| 9. |
- Serikova, Svetlana, et al.
(author)
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High riverine CO2 emissions at the permafrost boundary of Western Siberia
- 2018
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In: Nature Geoscience. - : Nature Publishing Group. - 1752-0894 .- 1752-0908. ; 11:11, s. 825-
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Journal article (peer-reviewed)abstract
- The fate of the vast stocks of organic carbon stored in permafrost of the Western Siberian Lowland, the world's largest peat-land, is uncertain. Specifically, the amount of greenhouse gas emissions from rivers in the region is unknown. Here we present estimates of annual CO2 emissions from 58 rivers across all permafrost zones of the Western Siberian Lowland, between 56 and 67 degrees N. We find that emissions peak at the permafrost boundary, and decrease where permafrost is more prevalent and in colder climatic conditions. River CO2 emissions were high, and on average two times greater than downstream carbon export. We suggest that high emissions and emission/export ratios are a result of warm temperatures and the long transit times of river water. We show that rivers in the Western Siberian Lowland play an important role in the carbon cycle by degassing terrestrial carbon before its transport to the Arctic Ocean, and suggest that changes in both temperature and precipitation are important for understanding and predicting high-latitude river CO2 emissions in a changing climate.
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| 10. |
- Vorobyev, Sergey N., et al.
(author)
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Permafrost Boundary Shift in Western Siberia May Not Modify Dissolved Nutrient Concentrations in Rivers
- 2017
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In: Water. - : MDPI AG. - 2073-4441. ; 9:12
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Journal article (peer-reviewed)abstract
- Identifying the landscape and climate factors that control nutrient export by rivers in high latitude regions is one of the main challenges for understanding the Arctic Ocean response to ongoing climate change. This is especially true for Western Siberian rivers, which are responsible for a significant part of freshwater and solutes delivery to the Arctic Ocean and are draining vast permafrost-affected areas most vulnerable to thaw. Forty-nine small- and medium-sized rivers (10-100,000 km(2)) were sampled along a 1700 km long N-S transect including both permafrost-affected and permafrost-free zones of the Western Siberian Lowland (WSL) in June and August 2015. The N, P, dissolved organic and inorganic carbon (DOC and DIC, respectively), particular organic carbon (POC), Si, Ca, K, Fe, and Mn were analyzed to assess the role of environmental parameters, such as temperature, runoff, latitude, permafrost, bogs, lake, and forest coverage on nutrient concentration. The size of the watershed had no influence on nutrient concentrations in the rivers. Bogs and lakes retained nutrients whereas forests supplied P, Si, K, Ca, DIC, and Mn to rivers. The river water temperature was negatively correlated with Si and positively correlated with Fe in permafrost-free rivers. In permafrost-bearing rivers, the decrease in T northward was coupled with significant increases in PO4, P-tot, NH4, pH, DIC, Si, Ca, and Mn. North of the permafrost boundary (61 degrees N), there was no difference in nutrient concentrations among permafrost zones (isolated, sporadic, discontinuous, and continuous). The climate warming in Western Siberia may lead to a permafrost boundary shift northward. Using a substituting space for time scenario, this may decrease or maintain the current levels of N, P, Si, K, Ca, DIC, and DOC concentrations in rivers of continuous permafrost zones compared to the present state. As a result, the export flux of nutrients by the small- and medium-sized rivers of the Western Siberian subarctic to the Arctic Ocean coastal zone may remain constant, or even decrease.
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