Assessing the potential of the MTG-FCI geostationary mission for the detection of methane plumes

The Flexible Combined Imager on the Meteosat Third Generation (MTG-FCI) provides geostationary observations over Europe and Africa, the Middle East, and parts of South America, and the surrounding waters. The FCI samples the visible, near-infrared and shortwave infrared spectral windows with a spatial resolution at nadir between 500 and 1000 m, and a 10-min temporal sampling. This configuration offers potential for methane retrievals using Multi-Band Multi-Pass retrieval (MBMP) methods, as shown with other multispectral missions. The potential of the MTG-FCI system for the detection and monitoring of single methane plumes is evaluated in this paper through different approaches. End-to-end simulations using high-resolution WRF-LES methane plumes over Algeria showed that MTG-FCI can detect emissions as low as ~30 t/h, where initial plume signals become visible, with clearer detection above ~50 t/h. Additionally, mass-balance modeling estimated a minimum detection limit of ~20–30 t/h across the central MTG-FCI disk (GSD ≥ 1 km) under optimal conditions. We illustrate the use of the MTG-FCI for the monitoring and quantification of methane plumes using a real transient emission detection from a compressor station in Algeria (34.676° N, 6.191° E) on September 29, 2023, capturing its full evolution from 10:40 to 15:50 UTC. The estimated emission rate of 353 ± 78 t/h aligns with independent estimates from other satellites. These results highlight MTG-FCI’s ability to track large methane plumes in near real-time, complementing polar-orbiting sensors.