The objectives of the Horizon Europe project PARIS are to:

1. quantify top-down emissions from a selection of European countries of major GHGs and black carbon aerosol;
2.  quantify the contribution of major source sectors of GHG and BC emissions and organic matter aerosol abundance through the implementation of innovative measurement and analysis technologies;
3. derive time- and space-resolved flux estimates for GHGs with complex or uncertain source distributions (N₂O, F-gases);
4. produce draft Annexes to the annual National Inventory Reports for a selection of ‘focus’ countries.

Activities at Empa will build on our previous and ongoing achievements in N₂O isotope analysis to determine the intramolecular isotopic composition of N₂O emitted from agricultural sites. Measurements of intramolecular N₂O isotopic composition will be compared to the N₂O isotopic composition calculated by the stable isotope model for nutrient cycles, SIMONE, in conjunction with the biogeochemical model output to assess the relative contributions of nitrification and denitrification to total N₂O emission. Based on the isotopic tuning of biogeochemical models, we will derive temporally and spatially resolved national emissions for focus countries.