A33F-06 GEO-Ring: Monitoring Extreme Methane Releases From Geostationary Orbit

Abstract: We present a global survey of extreme methane releases using the GEO-Ring of SWIR-sensitive geostationary weather satellites: GOES, MTG, FY4, and Himawari. Together, these platforms provide near-global coverage for detecting large, transient methane releases at 1–2 km nadir pixel resolution with revisit times ranging from 15 minutes to <30 seconds. We first report final results from the 2024 Very Large Methane Release (VLMR) experiment, which validated plume retrievals and source-rate estimates for high-detection-threshold satellite instruments through coordinated observations of a planned pipeline blowdown event in New Mexico, USA. We then systematically cross-reference GEO observations with weekly TROPOMI detections of large methane plumes, yielding a dataset of more than 100 methane plumes observed from geostationary orbit. We use this dataset to characterize the distributions of source rate, release mass, and duration for the world's most extreme methane point sources. We find a strong inverse relationship between source rate and release duration, indicating that the largest sources are typically the shortest lived. We also quantify GEO detection rates and thresholds by instrument, continent, and surface type. Finally, we combine the GEO-derived distribution of release durations with TROPOMI plume detections and source-rate estimates to infer annual emissions from extreme methane releases and assess their contribution to the global methane budget.