Methylation of Mercury in Thawing Permafrost Soils Across the Circumpolar North

Temperatures of permafrost soils have increased by 0.39 ± 0.15°C in zones with continuous permafrost during the last decade (IPCC report on The Ocean and Cryosphere in a Changing Climate).

Future warming threatens to remobilize large amounts of Hg currently ‘locked’ in Arctic permafrost soils and to create ‘hot spots’ for Hg methylation.

The potential risk enhanced Hg methylation, i.e. formation of monomethylmercury (MeHg), pose on a pan-Arctic scale, or across systems, is however poorly known.

This research program aims to address this knowledge gap by producing pan-Arctic estimates of methylmercury (MeHg) stock and Hg methylation potential in northern permafrost soils.

We will do this by i) build a MeHg-database covering examples of all major permafrost deposits and thaw stages through a pan-Arctic field campaign ii) identifying timeframes and useful proxies for net Hg methylation across permafrost systems through laboratory studies and by characterization of e.g. bacterial communities and iii) applying acquired data with current efforts to characterize permafrost landforms and to model the potential lateral release of organic matter (OM) and pollutants in contrasting permafrost environments.

Our ambitions research program builds on synergies with the two ongoing EU H2020-funded projects Global Mercury Observation and Training Network in Support to the Minamata Convention (GMOS-Train) and NUNATARYUK.