Partitioning Canadian Oil and Gas Methane Emissions with TCCON and Aircraft Ethane Measurements

Ethane (C2H6) is co-emitted with methane (CH4) during fossil fuel extraction, processing, and transport, but has few natural sources. Measurements of C2H6 can therefore be used to partition fossil fuel CH4 emission sources. The Total Carbon Column Observing Network (TCCON) site at East Trout Lake, located in Boreal Canada, is equipped with both InGaAs and InSb detectors which enable simultaneous total column remote sensing measurements of CH4 and C2H6 among many other species. East Trout Lake also hosts routine low-altitude NOAA aircraft in situ profile measurements of CH4 and C2H6. We combine these data with in situ CH4 measurements from the Environment and Climate Change Canada tower network in a top-down hierarchical Bayesian inverse model to infer both fossil fuel CH4 fluxes and C2H6:CH4 emission ratios in two of Canada’s major oil producing provinces: Alberta and Saskatchewan.