The WeThaw project carries out research to examine Arctic rivers – windows into organic carbon stabilisation in permafrost soils
The impact of climate change on the permafrost landscape has never been clearer. Warming temperatures are degrading permafrost soils and amplifying the release of organic carbon from the landscape’s vast stock. Crucially, a portion of this soil organic carbon attaches to mineral elements to form nano-micron scale entities, termed colloids which are transported laterally through soils into river waters. Arctic rivers capture this permafrost soil signal and can be used as ‘fluvial seismometers’ to detect the effect of climate change on lateral mineral element-organic carbon transport.
As part of the WeThaw project, Catherine Hirst, postdoctoral researcher, examines the association between organic carbon and mineral elements in soil and river waters. This research combines soil and river water sampling with novel techniques of particle size separation and geochemical modelling to isolate the mineral element-organic carbon interactions in soils and rivers. A key aspect of this work is to target sampling periods, including the spring flooding and summer rain event, when there is a direct connection between the permafrost soils and the headwater stream. By applying our techniques during these understudied and crucial periods, we can probe into mineral element-organic carbon interactions in soils and provide a baseline for future monitoring of the effects of permafrost degradation on these interactions.