Coordinated satellite, aircraft, and ground-based observations of a large transient methane release

We present results from 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 imagers with high point-source detection limits. The experiment coordinated observations of a U.S. gas pipeline blowdown with nine satellites, two 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 uncertainty. Best methane retrieval precision (7–8%) was achieved in the 7-s and 30-s mesoscale scan modes averaged to 5 min. Source-rate and mass estimates are broadly consistent across measurement platforms. Detectable emissions totaled 370±30 t over 44–65 min from two release points, ~25% lower than bottom-up expectations based on pipeline volume and nominal pressure, likely due to late-stage emissions below satellite detection limits. Our work provides a framework for evaluating high-detection-limit methane point-source imagers.