F-gases (here hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), NF₃ and SF₆): We will add new F-gas observations to cover a significant part of the European continent and expand top-down F-gas estimation to our focus countries. In addition, we will advance spatial disaggregation of bottom-up estimates using unique industry knowledge of the F-gas sector, thus creating a powerful combination of top-down and bottom-up information.

Methane (CH₄): We will advance the co-emitted tracer (stable isotope ratios, ethane) approach for sectoral CH₄ estimation by employing new continuous measurements in important regions where the source partitioning is not well-known.

Nitrous oxide (N₂O): We will improve the accuracy of two Tier-3 process-based biogeochemical models to simulate N₂O fluxes. This will be performed through site-scale model improvement based on N₂O isotopic analysis and country-scale assessment through high-resolution atmospheric inverse modelling.

Carbon dioxide (CO₂): We will advance the ability to partition top-down estimates of CO₂ emissions into fossil fuel and biosphere components by delivering new atmospheric APO measurement and modelling capabilities. Then we will explore the limits of detectability of future CO₂ flux changes in the European measurement network, to determine whether the system is up to the task of monitoring our transition to net zero.

Black Carbon (BC) and Organic Matter (OM) aerosol: We will develop new OM modelling techniques to determine whether inventories are consistent with the OM concentrations inferred for the major source sectors. Finally, we will explore the scope for sector-level BC emissions inference in Europe by developing a new BC inversion framework.