Water quality impacts of mobilization of permafrost carbon & nitrogen in High Arctic watersheds

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The proposed research examines how climate-driven permafrost change will impact the abundance, composition and transport of carbon (C) and nitrogen (N) in High Arctic watersheds. This research is necessitated by the fact that the permafrost is a significant store of C and N, and permafrost change stands to enhance the release, transformation, and mobilization of these important elements, which can significantly impact surface water quality, terrestrial and aquatic ecosystem function, and atmospheric C budgets. Despite the critical potential impacts, the vulnerability of permafrost-derived C and N to transport and cycling upon thaw is not well understood, especially in the High Arctic. This limited understanding is due to the heterogeneity in the composition and distribution of permafrost C and N, and an incomplete understanding of the hydrological and biogeochemical processes controlling their production, transport, and fate. ******These knowledge gaps will be addressed by combining a) studies of the abundance and chemical composition of permafrost C & N sources and how these vary across the landscape, with b) laboratory experiments that test the controls on the biogeochemical processes that alter and release permafrost C and N, and c) field investigations of how deeper thaw and subsurface hydrological changes affect C and N export and composition in surface waters. The research is novel as it links the geochemical and hydrological controls on C and N vulnerability to land cover specific sources and biogeochemical processes. The research will provide the knowledge necessary to develop landscape models to predict the impact of permafrost changes on downstream water quality and ecosystems and generate information to inform Arctic communities of the landscape and water quality elements that are sensitive to climate change. These results will guide governments in developing policy to protect ecosystems and water resources in anticipation of local climate change.******Highly qualified personnel (HQP) will be trained at the Cape Bounty Arctic Watershed Observatory (CBAWO), a collaborative research station that is unique in the Canadian Arctic. The rich integrated long-term observations and research legacy spanning 15 years of warming and permafrost change makes the CBAWO a valuable site that can serve as a model of High Arctic watershed response to climate change. The program will provide eleven HQP with the project management experience, field and analytical skills, and advanced knowledge required to assess the response of Arctic watersheds and ecosystems to climate change. The careers secured by graduates demonstrate that the knowledge and skills acquired are highly valued by industry and government. HQP will be poised to contribute to decision-making, and the development of practices that will improve the management of Arctic environments and water resources in a changing climate, and thus benefit the health and economic well being of all Canadians.**