Permafrost thaw drives iron and organic carbon release into soil pore water during palsa to degraded palsa transition

The dataset presents two files corresponding to the physical and the chemical properties of soil and soil pore water in Abisko (Sweden), at Stordalen Mire on a natural gradient of permafrost degradation (palsa, intermediate, and degraded palsa sites) between September and October 2021. Physical parameters such as soil water content (SWC), and soil temperature were measured at two depths (10 and 30 cm) every 10 minutes throughout the field campaign at the palsa and intermediate sites. At the degraded palsa site, SWC and soil temperature were measured at 10 cm depth four times during the campaign. Thaw depth was measured seven times during the campaign at every location (A, B, and C) of the three sampling sites (palsa, intermediate and degraded palsa sites). The elevation (n=9 for each sampling site) was measured from the digital elevation model generated from a very-high-resolution UAV flight using a RGB camera. The chemistry measurements comprise of the soil redox potential monitored every 30 minutes at two depths (12.5 and 30 cm) and soil pore water chemistry analyses. Samples of soil pore water (n = 164) were collected at the palsa, intermediate, and degraded palsa sites at 10, 30, and 60 cm depth (except 45 cm depth for the palsa site because the permafrost table reaches 50 cm depth). On soil pore water, we measured pH, conductivity, and concentrations in DOC (dissolved organic carbon) and major cations (Fe, Ca, K, Na, Mg, Mn, Al, P, Si).