Impact of permafrost thawing on aquatic ecosystems: quantification of chemical compounds inputs
Over half the below-ground terrestrial organic carbon (C) pool resides in permafrost soils that are currently thawing because of recent climate change. As a result, vast amounts of terrestrial carbon (C) are mobilized, having the potential to accelerate global warming. The enhanced transport of other elements (e.g. nutrients and pollutants) with thawing may also cause dramatic biogeochemical impacts such as eutrophication or high-latitude pollution in aquatic ecosystems. Despite the dramatic ecological effects of thawing permafrost, how this process occurs and the strength of the export of biochemical compounds to surface waters still represents one of the biggest uncertainties in our climate impact models. My project will fill this gap by providing the first quantification of both spatial and temporal variations in permafrost groundwater discharge (PGD) and its importance for both the C cycle and the quality of surface waters. The estimation of these fluxes will be assessed by applying a novel technique based on using radium (Ra) isotopes and radon (222Rn) as tracers of groundwater inputs.