On the 3rd of October we arrived in Abisko in northern Sweden, where we spent a week of fieldwork just two weeks after I started my PhD with the GMOS Train project. Abisko Naturvetenskapliga Station (ANS), is a scientific field research station managed by the Swedish Polar Research Secretariat and perfectly equipped and positioned to perform investigations in the surrounding environment. The main focus of our trip was to investigate mercury dynamics in thawing permafrost as part of WP3 of the GMOS Train project.

Northern permafrost soils store large amounts of mercury which is vulnerable to release as permafrost thaws over the next century. As part of the GMOS Train project, we particularly want to understand the mobility and transformation processes of terrestrial mercury that can emerge from thawing permafrost.

Under the supervision and coordination of Sofi Jonsson from the ACES group at Stockholm University, we took a transect of peat cores from peat upland through a pond at “Mellanflaket”. Here, we aim to determine mercury dynamics connected to the thaw gradient (Figure 1). Further, we took water samples from the same pond and surrounding water bodies, filtered them, measured active layer depths (Figure 2) and generally spent long evenings in the lab facilities at ANS preparing everything for transport. Another important part of my stay in Abisko was the start of an incubation experiment to identify potential methylation rates of mercury from arctic soils. For that, I added tracers of 199Hg and 201MeHg to selected samples in an oxygen free environment (Figure 3).

Now, sitting on the night train back to Stockholm, I am still dreaming of fall colored peat, birch forests and northern lights.

Figure 1: One of the ponds we sampled water from at Melanflaket. (picture: Charlotte Haugk)

Figure 2: Charlotte cutting peat (left) and filtering water in the evening light (right). (picture: Carluvy Baptista, Charlotte Haugk)

Figure 3: Charlotte working on samples inside the glove box. (picture: Carluvy Baptista)

by Charlotte Haugk