Feasibility and Applications of Retrieving Oil and Gas Ethane Emissions from Space

Ethane (C₂H₆) is a volatile organic compound (VOC) that reacts to form ozone, a harmful atmospheric pollutant. C₂H₆ has very few anthropogenic sources, and is primarily emitted from oil and natural gas (O&G) activities. This makes it an excellent tracer for O&G activities as a whole, as well as many important greenhouse gas and VOCs. Most notably, C₂H₆ is co-emitted with methane and has been shown to be useful in quantifying methane from O&G. Satellite data offers a unique opportunity to see trends in C₂H₆ emissions, as well as continue to monitor C₂H₆ going into the future. Here, we use the Cross-track Infrared Sounder (CrIS) onboard both the Suomi National Polar-orbiting Partnership and National Oceanic and Atmospheric Administration's NOAA-20 polar orbiting satellites to look at the previous 11 years of data. We develop an algorithm that quantifies the change in ethane absorption over the Permian basin. To prove the feasibility of the method, 2015 emissions, with O&G emissions validated by the Shale Oil and Natural Gas Nexus campaign are put into the Weather Research and Forecasting model coupled with Chemistry. Then, the C₂H₆ columns are put into the vector linearized discrete ordinate radiative transfer model and compared with satellite data. The results are also compared with methane satellite trends over O&G fields to compare how well CrIS captures the emission trends.