Tracking Ethane From Space Over a Large US Oil and Gas Region

Abstract

Ethane (C₂H₆) is a volatile organic compound (VOC) that has few anthropogenic sources, and is primarily emitted from oil and natural gas (NG) (O&G) activities. This makes it a useful tracer for distinguishing O&G activities from other sources of methane (CH₄) and non-methane VOCs. Here we use the Cross-track Infrared Sounder (CrIS) to develop a simple physical approach that quantifies the change in C₂H₆ absorption over the Permian basin. However, aircraft observations and the magnitude of the gradient in absorption across the basin suggests our model underestimates C₂H₆ emissions by a factor of ∼2. The 2014–2020 trend in C₂H₆ absorption is found to be increasing 5.6% ± 3.8% yr⁻¹, which suggests that the amount of VOCs emitted per amount of NG production has decreased by 23% yr⁻¹.