Abrupt permafrost collapse enhances organic carbon, CO2, nutrient and metal release into surface waters

Because the increase in the thickness of the thawing depth intensifies the input of inorganic components from deep mineral horizons, abrupt permafrost thaw enriches the surface waters in Al-rich colloids and low molecular weight organic complexes. As a result, the WSL's surface water colloidal composition may shift from DOM-rich and DOM-Fe-rich to DOM-Al-rich, and the release of low-soluble trivalent and tetravalent hydrolysates from the soil to the river will increase. We hypothesize that in sites of abrupt permafrost thaw, there is direct mobilization of soil waters to a hydrological network (rivers and lakes) and there is minimal transformation by autochthonous processes, which is unlike the case of steady permafrost thawing. Therefore, the change in physical factors, such as water pathways and the water residence time, within a given elementary landscape will likely control the overall impact of on-going permafrost thaw on both the surface water chemistry and dissolved greenhouse gas pattern of the territory. For this, high-resolution (< 2 m) remote sensing analysis of water dynamics in the permafrost landscape is necessary.