Inre Harrsjön

Inre Harrsjön is a 2.3 ha lake with a mean depth of 2.0 m and a maximum depth of 5.2 m. It is located in the Stordalen Mire, a peatland permafrost complex characterized by thawing permafrost in northern Sweden. The lake is not a thermokarst feature but instead formed after the last deglaciation (Kokfelt et al., 2010, doi:10.1007/s10933-010-9406-8). The sediments of the lake are organic-rich - mostly from internaly produced detritus - and produce large quantities of methane (Wik et al., 2018, doi:10.1029/2017JG004298). Long-term high-resolution measurements include water temperature profiles (2009-2019) as well as dissolved oxygen and specific conductivity (2015-2019). Manual observations include fluxes of methane (bubble traps and floating chambers) and carbon dioxide (gas transfer model) to the atmosphere and concentration profiles and stable isotope measurements of the same during the ice-free season as well as under-ice (Jansen et al., 2019, doi:10.1029/2019JG005094).