361 - Mercury Increase in Wet Atmospheric Precipitation in the Russian Arctic due to Regional Climate Change

In recent years a significant increase in the release of mercury into the Arctic atmosphere has been predicted due to the permafrost melting. This study has shown how regional differences in Hg concentration and deposition in the Arctic can vary on temporal and spatial scales. Event-based wet precipitations (rain and snow) were collected in the monitoring station organized at the urban area of the Yamal-Nenets Autonomous Area (YNAA). Nadym (65°32′ N 72°31′ E) is a circumpolar city located in the central part of the YNAA, 100 km south of the Arctic Circle. The average annual volume-weighted concentrations (VWC) in wet atmospheric precipitation in Nadym are comparable with the values obtained for other urbanized regions of the world; however, it is much higher than the values reported for remote Arctic places. Nevertheless, Hg annual deposition flux in Nadym is comparable to remote territories of the Arctic zone and less than annual fluxes in continental-scale monitoring networks of other parts of the world (USA, Europe, and China).

The seasonal study has shown that in winter, an increase in the mercury flux is mainly due to interannual seasonal variability of precipitation; however, there is a significant increase in the flux of wet atmospheric mercury deposition (by more than 30%) during the warm period of the year despite a decrease in the precipitation amount. In the warm period of the year, along with the other existing regional sources (emissions from fires, gas and oil combustion), a significant contribution can be observed already at present by the re-emission of mercury from soils, including seasonally thawed ones. The increase in the thickness of the seasonally thawed layer from 2017 to 2018 reached 30 cm in the Nadym region.

The research was carried out within the framework of the state task of IWEP SB RAS."

Authors: Stella Eyrikh, Liliya Shol, Elena Shinkaruk