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

Abstract

Increasing atmospheric temperatures in the Arctic have led to permafrost thawing and vertical downward migration of the active layer into formerly frozen ground during the thawing season (Christiansen et al.

Reemission of inorganic pollution from permafrost? – a freshwater hydrochemistry study in the lower Kolyma basin (North-East Siberia)

“…Both clusters may be connected to the suprapermafrost waters of the active layer, which are flowing intensely into the thermokarst lakes and rivers. Ji et al (2021) studied elements in permafrost soils and concluded that Mn, Ca, Mg, Al, and Ti showed the highest mobility from soil to suprapermafrost water and further into the ponds and flowing waters. Furthermore, they considered Mn a proxy for predicting the processes occurring in the active layer during summer-autumn thaw.…”

“…The supply of Cd may be connected to the drainage of mixed suprapermafrost water, which may include atmospheric deposition, and deeper water both. With the active layer deepening, atmospheric pollutants deposited in the past, which have been excluded from the freeze-thaw cycle for a time (Ji et al , 2021), may be remobilised (Edwards et al , 2021;Li et al , 2020;Limet al , 2019;Rubino et al , 2016). The notable increase in Cu, Ni, Pb and Zn concentrations in deep lake waters indicate the likely source of these elements in permafrost thaw, talik water, or enhanced mobility of suprapermafrost water eluting them from soil.…”

“…Hydrochemical changes in permafrost regions are increasingly probable, leading to both temporary and permanent hazards to the surface water quality in the Arctic (Brubaker et al , 2012;Gunnarsdóttiret al , 2019). Permafrost active layer deepening and the formation of new thermokarst lakes, taliks and drainage pathways (Dzhamalov & Safronova, 2018;in't Zandt et al , 2020;Tananaev & Lotsari, 2022) all lead to changes in the migration of chemical compounds (Frey & Mcclelland, 2009;Monhonval et al , 2021) both horizontally and vertically (Ji et al , 2021;Tananaev et al , 2021). The newly formed drainage pathways may leach chemical compounds from layers previously disconnected from groundwater flow (Jiet al , 2021;Lim et al , 2019).…”

“…The studies on the hydrochemical impacts of climate change in Siberian Arctic rivers have focused mainly on the organic carbon (OC) transport, including the dissolved OC (DOC), suspended particulate OC (POC) and riverbed sediment OC (SOC) (e.g., Holmes et al , 2012;Jonget al , 2022;Mann et al , 2012;Wild et al , 2019). Compared to the research on OC, the recognition of inorganic elements transport, including heavy metals, is relatively poor and limited to selected elements (Ji et al , 2021;Kuchmenko et al , 2002;Lim et al , 2019). Systematic research on the potential accumulation of heavy metals in permafrost has only been conducted on mercury (Wang et al , 2022).…”

A snap-shot assessment of carbon emission and export in a pristine river draining permafrost peatlands (Taz River, Western Siberia)

“…This recognition has motivated research aimed at understanding climate impacts on the sources and sinks of GHG in high latitude inland waters Hutchins et al, 2019;Zolkos et al, 2019;Dean et al, 2020). Of these numerous studies, only a few were conducted in the permafrost-affected rivers, typically at the scale of small watersheds (Denfeld et al, 2013;Serikova et al, 2018;Ji et al, 2020;Castro-Morales et al, 2022). Yet our knowledge of C cycling in so-called middle eight Arctic rivers (Severnaya Dvina, Pechora, Pur, Taz, Khatanga, Olenek, Yana, Indigirka) remains incomplete, preventing accurate quantification and prediction of C source-sink functions and responses to climate change.…”