NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area

Tags: greenhouse gases, atmospheric sciences, earth science, river emissions

Objective(s): To transform our understanding of how greenhouse gas emissions from rivers will impact the future trajectory of atmospheric carbon dioxide (CO2) and methane (CH4) concentrations.

Project Description: This licence has been issued for the scientific research application No. 5624. The main goal of this research is to better understand how greenhouse gas emissions from rivers will impact the future trajectory of atmospheric carbon dioxide (CO2) and methane (CH4) concentrations. The research team has identified two key research objectives that will allow them to address major research gaps in this carbon flux: 1) conduct river-borne measurements of surface water CO2 and CH4 release (and age and source) at a high spatial and temporal resolution to create a time series and footprint of greenhouse gas release from the Mackenzie River; 2) establish the release of trace elements from soils, sediments and rocks in the Peel, Arctic Red and Mackenzie rivers. The methods to be used are tied to the objectives, they are as follows: 1) the team will sample river surface CO2 and CH4 concentrations using high-frequency gas sensors which will be custom fitted onto the research vessels. Alongside, river water will also be collected in vials, sampled using a 60 ml syringe and mixed with ambient air by vigorous shaking for 1 min. The head-space will then be injected under overpressure into pre-evacuated exetainers which will be transported to the UK for storage. These samples will be analyzed at the University of Bristol using a gas chromatography isotope ratio mass spectrometry (GC-iRMS) and University of Glasgow, who will use Accelerator Mass Spectrometry (AMS) for isotopic composition of CH4 and CO2 respectively; 2) the research team will sample soil and sedimentary pore waters in the Mackenzie Delta region. Samples will be collected using Rhizon filters at multiple depths in sedimentary exposures. Filtered water will be stored in acid pre-cleaned high-density polyethylene (HDPE) bottles and shipped to the UK for storage. In Oxford, the geochemistry of these samples will be analyzed by inductively coupled plasma mass spectrometry (ICPC-MS) to quantify concentrations of trace metals. When the research team visits local communities they will take time to explain the approach and the methods and answer any questions people may have. The team will revisit communities to explain findings as the project moves forward. The team will also provide summaries in non-technical language to explain the main findings that have been made. This involves the possibility of collaborative research between those in the community, as well as opportunities for additional assistants associated with sample collection. The fieldwork for this study will be conducted from October 13, 2023 to December 31, 2023.