Constraints on methane emissions in North America from future geostationary remote-sensing measurements

摘要: Abstract. The success of future geostationary (GEO) satellite observation missions depends on our ability to design instruments that address their key scientific objectives. In this study, an Observation System Simulation Experiment (OSSE) is performed quantify the constraints methane (CH4) emissions in North America obtained from shortwave infrared (SWIR), thermal (TIR), and multi-spectral (SWIR+TIR) measurements orbit SWIR low-Earth (LEO) measurements. An efficient stochastic algorithm used compute information content inverted at high spatial resolution (0.5°  ×  0.7°) a variational framework using GEOS-Chem chemistry-transport model its adjoint. Our results show sub-weekly timescales, GEO can constrain about twice as many independent flux patterns than LEO orbit, with degree freedom for signal (DOF) inversion 266 115, respectively. Comparisons between TIR configurations reveal poor boundary layer sensitivities cannot be compensated by spatiotemporal sampling orbit. benefit instrument compared current products context shown timescale constraints, increase DOF 50 % 3-day inversion. further suggest both orbits could almost fully resolve CH4 fluxes least 100 km  ×  100 km over source hotspots (emissions  >  4  ×  105 kg day−1). sensitivity optimized emission scaling factors typical errors initial conditions reach 30 or configurations, respectively, while it smaller 5 % case system. Overall, demonstrate platform would need higher greatly mitigating impact inherent uncertainties methods inferred fluxes.