Global Tracking and Quantification of Oil and Gas Methane Emissions from Recurrent Sentinel-2 Imagery

Abstract

Methane (CH 4 ) emissions estimates from top-down studies over oil and gas basins have revealed systematic under-estimation of CH 4 emissions in current national inventories. Sparse but extremely large amounts of CH 4 from oil and gas production activities have been detected across the globe, resulting in a significant increase of the overall O&G contribution. However, attribution to specific facilities remains a major challenge unless high-resolution images provide the sufficient granularity within O&G basin. In this paper, we monitor known oil-and-gas infrastructures across the globe using recurrent Sentinel-2 imagery to detect and quantify more than 800 CH 4 leaks.In combination with leak emissions estimates from airborne and Sentinel-5P measurements, we demonstrate the robustness of the fit to a power law from 100 kg CH 4 /hr to 600 t CH 4 /hr. We conclude here that the prevalence of ultra-emitters (>25t CH 4 /hr) detected globally by Sentinel-5P directly relates to leak occurrences below its detection

Quantifying methane emissions from the global scale down to point sources using satellite observations of atmospheric methane

“…Multispectral instruments such as Sentinel-2, Landsat, and WorldView-3 are also capable of detecting and quantifying very large point sources (Varon et al, 2021;Ehret et al, 2022;Sanchez-Garcia et al, 2022;Irakulis-Loitxate et al, 2022a). Sentinel-2 and Landsat provide global and freely accessible data that could form the foundation of a global detection system for super-emitters (Ehret et al, 2022). A large-scale survey of point emissions across the western coast of Turkmenistan was achieved with the combination of Sentinel-2 and Landsat (Irakulis-Loitxate et al, 2022a).…”

“…An increased frequency of observation can identify persistence of emissions to enable corrective action, and better understanding of point sources that are intermittent by design can lead to better quantification of time-averaged emissions. Beyond this short-term intermittency, there is also long-term variability related to operating practices and facility life cycle (Cardoso-Saldaña and Allen, 2020;Johnson and Heltzel, 2021;Varon et al, 2021;Allen et al, 2022;Ehret et al, 2022), stressing the importance of sustained long-term monitoring.…”

“…Targeted observation of methane point sources from space began with the 2015 Aliso Canyon blowout using the Hyperion hyperspectral sensor (Thompson et al, 2016) and has since continued with the GHGSat instruments (2016-present, 25 × 25 m 2 pixels; Jervis et al, 2021). Hyperspectral land-imaging spectrometers (measuring continuous spectra with ∼ 10 nm resolution in selected wavelength channels) and multispectral land-imaging spectrometers (measuring radiances in discrete ∼ 100 nm channels) have also demonstrated capability to detect large methane point sources in their SWIR bands (Cusworth et al, 2019;Guanter et al, 2021;Varon et al, 2021;Ehret et al, 2022;Sanchez-Garcia et al, 2022).…”

Single-blind validation of space-based point-source methane emissions detection and quantification

“…This is due to the large effective pixel size of the TROPOMI instrument, roughly 7x7 km 8 . Sentinel-2 and Landsat 8 passively cover nearly the entire world's landmass with per-satellite revisit times of 10 and 16 days, respectively, with teams reanalyzing these data advertising minimum detection limits of 1-3 t/h 5,13 . GHGSat, PRISMA, and WorldView 3 are targeted "point-and-shoot" instruments, facilitating minimum detection levels claimed to be as low as 0.1 t/h at the expense of comprehensive spatial coverage 9,18,19 .…”

“…Existing satellite validation efforts largely focus on the consistency of quantification estimates across satellites and methods 5,11,13 , or rely on internal and generally unpublished controlled methane release testing. Although independent blind testing has become commonplace for terrestrial and airborne methane sensing technologies, to our knowledge there has until now been no such testing of the methane detection and quantification capabilities of satellites [14][15][16] .…”