https://vital.lib.tsu.ru/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000616152 Wed 29 Nov 2017 15:03:13 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000720803 Wed 27 May 2020 09:48:30 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001133263 Wed 24 Apr 2024 10:14:15 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001133267 50% of the annual export of DOC and generally insoluble trace metals. However, the winter baseflow provided sizable proportions of mobile elements such as DIC, major anions, cations, alkaline-earth elements, trace oxyanions and uranium. The size distribution of riverine solutes demonstrated 20–50% of DOC in the colloidal (3 kDa – 0.45 μm) form, dominance of low molecular forms (< 3 kDa) of soluble elements (alkali, alkaline earths, anions and neutral molecules) and essentially colloidal status of divalent metals (Cu, Zn, Cd, Pb, Ni), trivalent and tetravalent hydrolysates and U (from 30 to 93%). Seasonal variations in colloidal fractions of riverine solutes were consistent with the main mechanisms of element mobilization from the watershed to the Pechora River, as reflected in the 3 groups of elements according to their concentration – discharge relationship. Based on the present study and results of other mid-sized Arctic rivers (Severnaya Dvina, Taz), we demonstrate that mean discharges and solute concentrations in August can be used to adequately (± 20%) approximate mean annual values, hence allowing annual flux assessment via single month sampling campaign. A comparison of contemporary yields of Ca, Mg, Cl, SO4, DIC and DOC against historical data for the Pechora River basin demonstrated reasonable agreement within the inter-annual variations that is consistent with long-term data series on other Arctic rivers.]]> Wed 24 Apr 2024 10:00:15 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000901829 Wed 19 Oct 2022 10:09:09 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000645268 0.5 ha is 727,700, with a total surface area of 5.97 million ha, yielding an average lake coverage of 5.69% of the territory. Small lakes (0.5–1.0 ha) constitute about one third of the total number of lakes in the permafrost-bearing zone of WSL, yet their surface area does not exceed 2.9% of the total area of lakes in WSL. The latitudinal pattern of lake number and surface coverage follows the local topography and dominant landscape zones. The role of thermokarst lakes in dissolved organic carbon (DOC) and most trace element storage in the territory of WSL is non-negligible compared to that of rivers. The annual lake storage across the WSL of DOC, Cd, Pb, Cr, and Al constitutes 16%, 34%, 37%, 57%, and 73%, respectively, of their annual delivery by WSL rivers to the Arctic Ocean from the same territory. However, given that the concentrations of DOC and metals in the smallest lakes (<0.5 ha) are much higher than those in the medium and large lakes, the contribution of small lakes to the overall carbon and metal budget may be comparable to, or greater than, their contribution to the water storage. As such, observations at high spatial resolution (<0.5 ha) are needed to constrain the reservoirs and the mobility of carbon and metals in aquatic systems. To upscale the DOC and metal storage in lakes of the whole subarctic, the remote sensing should be coupled with hydrochemical measurements in aquatic systems of boreal plains.]]> Wed 19 Dec 2018 14:12:33 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000474702 Wed 12 Dec 2018 18:17:49 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000487023 Wed 12 Dec 2018 17:53:05 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000576414 Wed 07 Jun 2017 14:26:14 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000518079 Wed 05 Dec 2018 10:15:21 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000893572 99 % CO2, <1 % CH4), which is comparable with CO2 emission measured in the Kolyma, Yukon, and Mackenzie rivers and permafrost-affected rivers in western Siberia. The areal C emissions from lotic waters of the Lena watershed were quantified by taking into account the total area of permanent and seasonal water of the Lena basin (28 000 km2 ). Assuming 6 months of the year to be an open water period with no emission under ice, the annual C emission from the whole Lena basin is estimated as 8.3±2.5 TgCyr-1, which is comparable to the DOC and dissolved inorganic carbon (DIC) lateral export to the Arctic Ocean.]]> Wed 04 May 2022 14:38:52 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000653315 Tue 14 May 2019 09:38:15 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000996389 Tue 14 Feb 2023 15:56:42 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000996386 Tue 14 Feb 2023 15:56:39 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000996385 Tue 14 Feb 2023 15:56:37 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000996387 Tue 14 Feb 2023 15:56:35 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000996388 10. The difference in the degree of C removal between different species was primarily linked to different degree of pH rise during photosynthesis. Taken together, the results obtained in this study allowed an efficient reproduction of combined magnesium hydroxo-carbonates and hydrous silicates precipitation under cyanobacterial activity, suitable for geoengineering of biologically controlled CO2 sequestration in Si-Mg-carbonate-bearing solutions]]> Tue 14 Feb 2023 15:56:34 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000794662 Tue 09 Mar 2021 13:25:37 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000897060 0.75‰/°C) were observed at continental sites, while statistically significant temperature relations were generally absent at coastal stations. Model outputs indicate that 68% of the summer precipitating air masses were transported into the Arctic from mid-latitudes and were characterized by relatively high δ18O values. Yet 32% of precipitation events, characterized by lower δ18O and high d-excess values, derived from northerly air masses transported from the Arctic Ocean and/or its marginal seas, highlighting key emergent oceanic moisture sources as sea ice cover declines. Resolving these processes across broader spatial-temporal scales is an ongoing research priority, and will be key to quantifying the past, present, and future feedbacks of an amplified Arctic water cycle on the global climate system.]]> Thu 30 Jun 2022 12:12:45 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001133432 80 times) impoverished compared with UCC and RSM. Taken together, the elemental composition of macroaggregates allows for distinguishing the lithogenic and biogenic impacts on the occurrence of these unique large-scale mucilage events, linked to the exometabolism of marine plankton combined with the input of allochthonous inorganic material.]]> Thu 25 Apr 2024 09:48:16 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001133433 Thu 25 Apr 2024 09:48:13 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001009377 30 %, regardless of season) variations between day and night. The CH4 concentrations and fluxes increased in the order “spring ≤ summer < autumn” and ranged from 1 to 15 μmol L−1 and 5 to 100 mmol m−2 d−1, respectively. The CO2 concentrations and fluxes (range from 100 to 400 μmol L−1 and 1 to 4 g C m−2 d−1, respectively) were positively correlated with dissolved and particulate organic carbon, total nitrogen and bacterial number of the water column. The CH4 concentrations and fluxes were positively correlated with phosphate and ammonia concentrations. Of the landscape parameters, positive correlations were detected between riparian vegetation biomass and CO2 and CH4 concentrations. Over the six-month open-water period, areal emissions of C (>99.5 % CO2; <0.5 % CH4) from the watersheds of 11 rivers were equal to the total downstream C export in this part of the WSL. Based on correlations between environmental controllers (watershed land cover and the water column parameters), we hypothesize that the fluxes are largely driven by riverine mineralization of terrestrial dissolved and particulate OC, coupled with respiration at the river bottom and riparian sediments. It follows that, under climate warming scenario, most significant changes in GHG regimes of western Siberian rivers located in permafrost-free zone may occur due to changes in the riparian zone vegetation and water coverage of the floodplains.]]> Thu 16 Nov 2023 11:51:49 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000486249 Thu 13 Dec 2018 10:36:50 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001008913 99.5% C-CO2, <0.5% C-CH4) which is twice higher than the total dissolved C (organic and inorganic) riverine export flux during the same period. Applying a “substituting space for time” approach for northern and southern parts of the river basin, we suggest that the current riverine CO2 emission may increase 2 to 3 fold in the next decades due to on-going climate warming and permafrost thaw. When integrating the obtained results into global models of C and biogeochemical cycle in the Arctic and subarctic region, the use of the Taz River as a representative example of continental planes should help to estimate the consequences of frozen peatland thaw on CO2 cycle in the Arctic and subarctic regions.]]> Thu 09 Nov 2023 09:56:02 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001008912 70% of annual Mn flux occurred in winter. A number of elements present in the snowpack exhibited sizable (> 45%) export during spring flood (Zn, Cu, Pb, Cd, Sb and Cs). The 3 years mean export fluxes (yields) of dissolved components were comparable to or 30–50% lower than those of other large and medium sized Arctic rivers. This was due mostly to a lack of fresh unaltered rocks and a dominance of peatlands within the Taz River watershed. Elevated concentrations of redox-sensitive micro-nutrients (such as Fe and Mn) occurring during winter baseflow can be linked to disproportionally large floodplain zone of this river which can act, especially in the river's lower reaches, as a stratified lake thereby releasing high amounts of redox-sensitive elements from the sediments. The role of suboxic zones in the Arctic boreal riverine landscape may be more important than previously thought, and may allow explaining anomalously high concentrations of some metals (i.e., Mn) reported in Arctic Ocean surface waters. It is anticipated that climate warming in the region may increase the contribution of winter flow and enhance the export of soluble elements and some nutrients (such as Si, Mn and Co).]]> Thu 09 Nov 2023 09:55:57 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000895622 Thu 09 Jun 2022 23:41:56 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001067505 Thu 08 Feb 2024 10:56:19 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000897489 Thu 07 Jul 2022 14:08:44 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000659757 Thu 04 Jul 2019 10:25:26 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000894992 Thu 02 Jun 2022 10:40:31 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000513568 Sat 11 Nov 2017 13:06:46 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001139591 Mon 27 May 2024 15:57:04 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000897643 Mon 22 Aug 2022 10:41:59 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000925495 Mon 19 Dec 2022 15:45:40 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000901388 Mon 17 Oct 2022 14:24:10 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000446245 Mon 17 Dec 2018 13:12:07 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000494602 Mon 17 Dec 2018 09:55:58 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000795004 Mon 15 Mar 2021 09:04:34 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000996329 Mon 13 Feb 2023 14:23:40 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000487024 Mon 10 Dec 2018 16:01:22 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000500857 Mon 10 Dec 2018 15:54:12 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000528604 summer>autumn>winter. The ice formation in October included several stages: first, surface layer freezing followed by crack (fissure) formation with unfrozen water from the deeper layers spreading over the ice surface. This water was subsequently frozen and formed layered ice rich in organic matter. As a result, the DOC and metal (Mn, Fe, Ni, Cu, Zn, As, Ba and Pb) concentrations were highest near the surface of the ice column (0 to 20 cm) and decreased by a factor of 2 towards the bottom. The main implications of discovered freeze-driven solute concentrations in thermokarst lake waters are enhanced colloidal coagulation and removal of dissolved organic matter and associated insoluble metals from the water column to the sediments. The measured distribution coefficients of a TE between amorphous organo-ferric coagulates and lake water (<0.45 μm) were similar to those reported earlier for Fe-rich colloids and low molecular weight (<1 kDa, or <1–2 nm) fractions of thermokarst lake waters, suggesting massive coprecipitation of TE with amorphous Fe oxyhydroxide stabilized by organic matter. Although the concentration of most elements was lowest in spring, this period of maximal water coverage of land created a significant reservoir of DOC and soluble metals in the water column that can be easily mobilized to the hydrological network. The highest DOC concentration observed in the smallest (<100m2) water bodies in spring suggests their strongly heterotrophic status and, therefore, a potentially elevated CO2 flux from the lake surface to the atmosphere.]]> Mon 10 Dec 2018 12:52:19 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000453489 Fri 14 Dec 2018 09:49:57 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000490055 Fri 14 Dec 2018 09:42:50 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000794754 Fri 12 Mar 2021 13:24:33 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001008660 Fri 03 Nov 2023 09:29:51 KRAT ]]>