NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area

Tags: water quality, air quality, greenhouse gases, polar atmosphere

Objective(s): To continuously monitor environmental data such as greenhouse gasses (carbon dioxide and methane) and standard oceanographic parameters in surface water/water column and the polar atmosphere.

Project Description: This licence has been issued for the scientific research application No. 5623. This project will be supervised by UNIGE, Geneva University and conducted onboard by Noémie Planat, a PhD student at McGill University. This study will continuously monitor environmental data (greenhouse gasses (carbon dioxide and methane) and standard oceanographic parameters in surface water/water column, and the polar atmosphere. The Arctic plays a crucial role in the global cycle of the main carbon-based greenhouse gases: methane (CH4) and carbon dioxide (CO2). The study carried out here aims to measure and quantify the fluxes of CO2 and CH4 between the Arctic Ocean and atmosphere, as well as the distribution of their stable isotopes: carbon (d13C), between the Arctic Ocean and the atmosphere. It is known that high-latitude seas are important CO2 sinks. In contrast, the Arctic is, to a lesser extent, a source of methane with a warming potential greater than CO2. Greenhouse Gasses (GHG) flows are, and will be, impacted by current environmental changes. It is crucial to determine if the Arctic's role in mitigating global warming will be compromised. This study will improve our understanding of the contribution of the polar regions to global climate change. This is the 4th year of the Changing Arctic expedition collecting these data to compile a GHG data base, and to assess the fluxes of these GHGs. The short-term and long-term goals are: 1) To monitor atmospheric and surface water concentrations of CH4 and CO2 and their stable carbon isotopes (d13C). To measure surface water temperature, salinity, and dissolved oxygen. These data will be used to assess the role of the North-West passage in CO2 uptake and CH4 emissions; 2) The longer-term adjectives are to provide additional data in the Arctic region to add to the CO2 and CH4 budgets for the region, as well as temperature data. The purpose of this research project is to characterize the water properties (temperature and salinity) of Alaskan coastal current carrying summer Pacific Waters along the continental shelf at a depth of 50-100, and potentially identify eddies breaking off the shelf and carrying warmer summer Pacific Waters offshore into the Canada Basin. The atmospheric GHG concentrations are measured in real-time from a Portable Greenhouse Gas Analyzer. This instrument measure the CO2, CH4, and H2O gases in ppm. The machine constantly draws in air at the top of the sailboat mast, which passes through a chamber with two mirrors where lasers move back and forth between them with a certain wavelength. A multiparameter probe (CTD) is installed in the hull of the sailboat and measures every minute the temperature [°C], conductivity [µs/cm], TDS total dissolved solids [mg/l], turbidity [FNU], salinity, optical dissolved oxygen, TSS, pressure and depth. The multiparameter probe is positioned just below the surface so that it can always remain in the water, even during navigation. Manual sampling is performed to quantify CO2 and CH4 concentrations in the surface water. The sampling is done using the “headspace” method which equilibrates the gas molecules in the aqueous phase and those in the gaseous phase. These samples are shipped to University of Geneva and analyzed in the laboratory with the Picarro stable isotope analyzer (CH4 and CO2). Vertical profiles of Temperature and Salinity will be done along the continental shelf from Tuktoyaktuk to Utqiagvik and along transects perpendicular to the coastline at six different locations between Tuktoyaktuk and Utqiagvik. The measurements will be carried using a MicroCat Conductivity-Temperature-Depth (CTD) instrument from the ocean surface to 200 m depth. Communication on the project and project review is ongoing with First Nations from the Inuvialuit Settlements. To engage with the local community, the Arctic Expedition combines navigation and environmental research with outreach activities onboard, at ports of call: Tuktoyaktuk. The fieldwork for this study will be conducted from August 22, 2023 to September 10, 2023.