Coordinated satellite, aircraft, and ground-based observations of a large transient methane release
Researchers from the Varon Lab conducted a unique experiment with NOAA that involved flying an aircraft, driving a truck-based laboratory, and operating nine satellites to observe methane emissions from a planned industry release, which enabled the first direct validation of the satellites’ methane data products.
Methane is a potent greenhouse gas, and emissions from oil and gas infrastructure are a major mitigation target. Satellites are increasingly used to detect and quantify these emissions, but evaluating their estimates of releases remains challenging. In this study, researchers analyzed a US gas pipeline blowdown in New Mexico using coordinated observations from nine satellites, an aircraft, and a truck-based mobile laboratory.
“It is rare to have this many space-based instruments looking at the same release at the same time, and we would like to make it routine,” says Tailong He, a senior postdoctoral researcher in the Varon Lab and lead author on the paper, which was published in PNAS this September. “The appeal is that we don’t put additional methane into the atmosphere. These blowdowns are already on the calendar, and they give us a chance to better understand these kinds of short-lived emission activities that are difficult to quantify with conventional methods.”
The experiment provides a rare opportunity to evaluate the accuracy of satellite-based observations of large, short-lived methane point sources. The researchers show that geostationary satellites can continuously track and quantify such releases, with emission estimates consistent with other platforms and expectations from pipeline pressure and volume. The results build confidence in satellite observations to monitor extreme methane releases worldwide.
“Coordinating with industry is the only way to validate satellite and suborbital measurements of these extreme methane releases, which are regularly detected around the world from space,” says Daniel Varon, Boeing Career Development Professor of Aeronautics and Astronautics and the paper’s senior author. “Conventional controlled release testing frameworks don’t work because they would be too expensive and dangerous at these magnitudes.”
Authors: He, T.-L., Varon, D. J., Kondragunta, S., Ren, X., Cohen, M. D., Carroll, B. J., Malarich, M., Peischl, J., de Jong, T. A., Gerritsen, J., Maasakkers, J. D., Cusworth, D. H., Duren, R. M., Brown, S. S., Warneke, C., Sweeney, C., Stratton, P., Brewer, A., Baidar, S., and Levin, E. J. T.
Citation: He, T.-L., Varon, D. J., Kondragunta, S., Ren, X., Cohen, M. D., Carroll, B. J., Malarich, M., Peischl, J., de Jong, T. A., Gerritsen, J., Maasakkers, J. D., Cusworth, D. H., Duren, R. M., Brown, S. S., Warneke, C., Sweeney, C., Stratton, P., Brewer, A., Baidar, S., and Levin, E. J. T.: Coordinated satellite, aircraft, and ground-based observations of a large transient methane release, Proc. Natl. Acad. Sci., https://doi.org/10.1073/pnas.2603595123, 2026.
Abstract
We present the results of a Very Large Methane Release (VLMR) experiment evaluating methane retrievals from the Geostationary Operational Environmental Satellites (GOES) Advanced Baseline Imagers (ABIs) and multiple low-Earth-orbit satellite instruments with high point-source detection thresholds. The experiment coordinated observations of a US gas pipeline blowdown with nine satellites, an aircraft, and a truck-based mobile laboratory. We used the GOES-16, -18, and -19 ABIs with revisits every 10 min to 7 s to quantify release magnitude and associated uncertainty. Best methane retrieval precision of 7% was achieved in the 30-s mesoscale scan modes averaged to 5 min, yielding an estimated methane plume detection threshold of 15 to 30 t h−1 per m s−1 of wind. GOES detected total emissions of 370 ± 30 t over 42 to 63 min from two release points. Source rate and mass estimates are broadly consistent across measurement platforms, but the total detected release mass is ~25% lower than that reported by the operator based on pipeline volume and pressure. This discrepancy may reflect late-stage emissions below satellite detection thresholds and indicates a potential low bias in satellite estimates of total emissions from large transient releases. Coordinated field experiments such as VLMR can complement existing controlled-release satellite evaluation programs by providing a framework to validate observations of very large methane point sources.
