(Greenland Lakes - Image: Jasmine Saros)
Chairs
Scope
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Freshwater systems serve as important biogeochemical reactors in the Arctic system.
Freshwater processes reflect rapidly changing features of the terrestrial catchments in which they are embedded. Arctic terrestrial linkages to aquatic systems occur through shallow groundwater connections, pulsed snow melt in the spring and active layer dynamics during the summer months, and perennial thaw zones (taliks). Arctic terrestrial ecosystems deliver dissolved, particulate, and gaseous forms of carbon and nutrients to inland freshwater systems. In turn, this affects the physical, chemical and biological structure and function of freshwater systems, and ultimately the dynamic balance between net autotrophy or heterotrophy. This action group will focus on key questions in Arctic land-water processes, specifically focusing on core Arctic system themes of connectivity, gradients, thresholds, and emergent properties. The group will identify sentinel responses of freshwater systems, and develop protocols and plans to track and assess these responses. |
Mackenzie Delta - June 2011
Great Whale River - Whapmagoostui-Kuujjuarapik, Nunavik, Canada
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T-MOSAiC Activities
- Dissolved oxygen (DO) is a sentinel variable in aquatic ecosystems, and has wide ranging implications for biogeochemistry, food webs and fish health. We will connect records of DO across the circumpolar north, with special attention to seasonal records that include the winter 2019-2020 overlap period with MOSAiC. We will identify best practices for high frequency automated measurements of DO and will identify other relevant variables for the future deployment of freshwater moorings in the Arctic. We will exchange expertise on DO modelling approaches in the context of climate change, and work toward synthesis data sets and papers that address T-MOSAiC system themes such as thresholds (e.g., hypoxia and anoxia), extreme events and gradients (e.g., as a function of DOC).
- ·Synthesis papers, including ‘Arctic lakes as sentinels’ and analyses across DOC gradients.
- Flowing water themes – carbon, nutrient and metal mobilization from thawing permafrost.
- For flowing water systems, potential activities could focus on nested catchment approaches to represent connectivity and gradients within watersheds enroute from the uplands to the ocean. We may use tracers as tools to provide broader monitoring across spatial and temporal scales. Stark contrasts in regional responses, caused by differences in landscape factors (ice content, relief, soil composition) should deserve particular focus, as well as regions that are most susceptible to thaw-induced change such as areas that experience substantial thermokarst or regions near the continuous-discontinuous transition.
Members (updated regularly)
Under construction
Under construction