During this field campaign GMOS Train PhD student Charlotte Haugk (ESR 8) and her supervisor Sofi Jonsson (WP3-lead) went to camp for 2 weeks in the peatlands of Tavvavuoma, an isolated permafrost site in northern Sweden. The field campaign was initiated by Julia Wagner (PhD student at Horizon2020 Nunataruyk project), who will estimate carbon stocks in area studied. In earlier studies, the amounts of carbon stored in Arctic permafrost soils have been used to map and estimate the stocks of total mercury. Based on the data generated from this field campaign, Charlotte and Sofi will together with a master student test if data on carbon, total mercury and the type of landscape can be used to map and estimate stocks of methylmercury in permafrost soils.

Figure 1: Map of the study area at Tavvavuoma and a picture of a palsa with a collapsing fen in front of it.
Figure 2: Sofi Jonsson, Julia Wagner and Charlotte Haugk in the field. Photo by Helen Ahlbom
Figure 3: The study area from the helicopter view: peat uplands, palsas with small lakes and fens in between.

The team spent the first week together with Britta Sannel (Department of Physical Geography, Stockholm University) and her master students Ida Rehn and Fabian Seemann at the first sampling site “Tavva South”. Helen Ahlbom, a photographer and artist, also joined the team for the first few days. The second week was spent at the second sampling site “Tavva North”, where Julia and Charlotte continued to collect soils cores.

During the two weeks in the field, 39 soil cores were sampled. These were collected by digging soils pits and hammering stainless steel pipes into the frozen part of the ground. In addition to the soil cores sampled, Charlotte and Sofi also collected water samples and measured the depth of the active layer (top layer of soil that thaws during the summer and freezes again during the autumn). They also collected leaves from the vegetation to study foliar Hg uptake from the atmosphere in collaboration with ESR9 Saeed Waqar Ali (also part of WP3)

Now, Charlotte and Sofi will have one week at home before they go to a second fieldwork this season at Abisko Research Station.

Figure 4: Impressions from the field: coring peat and permafrost and filtering water (Photos by Charlotte Haugk).