Change in water surface area northern Sweden

Abstract: Changes in water surface area (w.s.a.) in Arctic regions have been linked to climate warming and permafrost degradation (Briggs et al. 2014). As permafrost thaws, thermokarst lakes are formed. This causes the surface to get wetter. Although, a drying of the surface has often been observed in areas of discontinuous permafrost. As the climate warms, permafrost starts to thaw from underneath the lakes, causing drainage from below to be possible. The permafrost around lake Torneträsk, northern Sweden, has been degrading over the past few decades (Akerman and Johansson 2008), and a change in surface wetness has been observed (Christensen et al. 2004b). In this thesis, the change in w.s.a. of the Torneträsk region, as well as its relation to air temperature, precipitation, snow depth and active layer thickness has been investigated by analysing satellite images taken between 1990 to 2015. The w.s.a. in the Torneträsk region has been declining over the past 25 years. This decline however has only been observed in the permafrost free zones and the areas with sporadic permafrost. The areas underlain by continuous and discontinuous permafrost observed an increase in w.s.a. However, no significant relationships were found between the change in w.s.a. and climatic factors, since the study was too short.