MethaneSAT - Quantifying Methane Emissions on Basin-Scales From Space

Anthropogenic methane emissions, particularly from the oil and gas (O&G) sector, span a broad spectrum of rates and demonstrate significant temporal variability and intermittency. The MethaneSAT satellite addresses a critical limitation in space-based methane monitoring by enabling simultaneous quantification of both discrete point sources and diffuse area sources across regional scales, such as O&G production basins, using snapshot observations. MethaneSAT retrieves the total column dry-air mole fraction of methane (XCH₄) with high spatial resolution (100 m × 400 m) and precision (20–40 ppb) across observation swaths of 220 km × 200 km. Operating from March 2024 to June 2025, MethaneSAT acquired 1,152 scenes over 231 global targets, and to date, EDF has released over 190 emission maps spanning 49 O&G basins.

We present MSAT L4 CORE (MethaneSAT Level 4 Conserved, Optimized Retrieval of Emissions), an inverse modeling framework for quantifying regional-scale methane emissions. CORE employs Hamiltonian Monte Carlo sampling via the Stan software to infer posterior distributions of surface fluxes, conditioned on single-scene MethaneSAT measurements. Emissions are estimated in 4 km × 4 km grid cells, generating ensemble posterior flux distributions that reproduce the observations. A spatially homogeneous prior is imposed on the emissions, and regional-scale boundary inflow is estimated concurrently. MSAT L4 CORE enables regional-scale, snapshot emission estimates with typical uncertainties of 30% on aggregated emissions.

We demonstrate CORE using both simulated and real MethaneSAT data, and discuss its applicability to the airborne MethaneAIR mission as well as other airborne and spaceborne methane observing platforms.