https://vital.lib.tsu.ru/vital/access/manager/Index ${session.getAttribute("locale")} 5 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/vtls:000465282 Mon 17 Dec 2018 11:01:29 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:000494804 Fri 14 Dec 2018 09:43:00 KRAT ]]>