NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region

Tags: permafrost, carbon fluxes, biogeochemical processes, permafrost mapping, biogeophysical processes, lake permafrost, watershed

Objective(s): To investigate biogeochemical and biogeophysical processes along transects following landscape gradients, and study carbon cycle processes within small to medium-sized lakes and watersheds. Transects in the vicinity of the Trail Valley Creek camp were sampled during field work in 2022 and 2023, and the plan is to revisit these sites in summer 2024 to continue the campaign.

Project Description: This licence has been issued for the scientific research application No. 5971. As part of the ERC-synergy project Q-Arctic, we plan to investigate biogeochemical and biogeophysical processes along transects following landscape gradients, and study carbon cycle processes within small to medium-sized lakes including their watersheds. Gradients on land include natural variability within heterogeneous permafrost landscapes, such as e.g. a transect from dry upload tundra into a lower lying wetland area, but we are particularly interested in disturbance features (e.g. thermokarst, erosion, alas formation, ice-wedge degradation) within the Arctic permafrost region. Suitable transects in the vicinity of the Trail Valley Creek camp have already been sampled during field work in 2022 and 2023, and we plan to revisit these sites in summer 2024 to continue the campaign. Additional observational components to be added this year include floating chambers to measure carbon processes and environmental characteristics on lakes, and drone flights for in-situ measurements of greenhouse gas concentrations in the lower atmosphere. These components are supposed to provide new insights into the role of water bodies for tundra net carbon exchange budgets, and in case of the drone integrate exchange processes across larger heterogeneous tundra landscapes. The aim of all observations is to characterize the changes in carbon (CO2, CH4) and energy cycles that go along with the permafrost gradients/degradation, allowing to better understand the future feedbacks of currently undisturbed Arctic landscapes with an expected warmer climate. Associated shifts in vegetation communities, as well as hydrological and soil conditions will also be investigated in detail. Within this framework, these fieldwork-based projects will closely interact with, and get support from, research activities within the other project components of Q-Arctic, including multi-disciplinary in-situ observations, satellite remote sensing and land-surface modeling at regional to pan-Arctic scales. Our terrestrial field work activities will be based on mobile flux chamber measurements, and ancillary observations, to characterize the small-scale variability in carbon and energy exchange between permafrost ecosystems and the atmosphere. The team that will be executing the field experiments will be equipped with a portable greenhouse gas analyzer for CH4/CO2/H2O mixing ratios (Licor LI-7810) and with ancillary sensors (e.g. temperature, radiation) as well as push-in probes for soil temperature, humidity, and pH. On a very limited scale, additional soil and vegetation samples are supposed to be taken for subsequent analysis in the lab. Lake measurements will use small flotation devices equipped with gas analyzers (VAISALA GMP, LosGatos micro-portable gasanalyzer) and ancillary instrumentation to observe exchange fluxes of CO2 and CH4 as well as environmental conditions and water body characteristics. Flotation devices will be moved across different sections of the studied lakes to investigate spatial variability in lake conditions and carbon fluxes, e.g. linked to gradients in bathymetry. Finally, our drone will carry small meteorological instruments next to 2 gas analyzers for CO2 (Licor LI-850) and CH4 (Aeris STRATO). With a mean flight time of around 20 minutes per battery set, this observation system allows us to sample the variability of greenhouse gas concentrations in the lower atmosphere over heterogeneous tundra areas, aiming at constraining fluxes from different landscape elements such as e.g. dry upland tundra, wetlands, or lakes. Since we only recently started our research program in the Inuvik region, besides the contacts to our Canadian researcher colleagues that have been active in the Inuvik region for longer periods there are only first contacts established with other parts of the communities yet. However, we are eager to continue collaborating with community members, ideally embedding them into our research, and also coordinate our planned research activities with local groups and communities. Of course results will also be shared with local, federal and territorial government agencies, if there is interest. The fieldwork for this study will be conducted from: June 22 - August 31, 2024