High-Resolution Inversion Modeling of Carbon Dioxide and Methane Emissions in Europe: Assessing Accuracy and Dynamics

Accurate estimation of critical greenhouse gas fluxes, particularly carbon dioxide (CO2) and methane (CH4), is vital for shaping effective climate change policies. Leveraging the state-of-the-art Community Inversion Framework (CIF), we estimate high-resolution emissions across Europe (-12E to 37E, 35N to 73N). Using the Lagrangian Particle Dispersion Model (FLEXPART) with ECMWF meteorological data, we calculate surface flux footprints at 0.2 0.2 resolution, enhancing comparisons with national inventories. Assimilating data from 40+ in-situ observations, including ICOS and non-ICOS stations, our 4-dimensional variational optimization refines prior high-resolution flux estimates. Diverse sources contribute to the total flux, including fossil fuel emissions, biomass burning, land emissions, air-sea exchange. Flux corrections enhance accuracy, yielding posterior estimates with reduced bias and heightened correlation. Major CH4 emitters (France, Germany, Italy, Spain, Poland, and the UK) collectively contribute 72% of total emissions. The EU27 + UK average is 16.47 1.33 Tg CH4/yr. Posterior anthropogenic emissions reveal a regional mean reduction of > 5 gC/m2/month in summer compared to prior estimates, highlighting seasonal emission dynamics.