Do alternative inventories converge on the spatiotemporal representation of spring ammonia emissions in France?

Audrey Fortems-Cheiney (1, 2, 3) , Gaelle Dufour (2, 1) , Karine Dufossé (4) , Florian Couvidat (5) , Jean-Marc Gilliot (4) , Guillaume Siour (2, 1) , Matthias Beekmann (2, 1) , Gilles Foret (2, 1) , Frédérik Meleux (5) , Lieven Clarisse (6) , Pierre-François Coheur (6) , Martin van Damme (6) , Cathy Clerbaux (7, 6) , Sophie Génermont (4)

1 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
2 LISA (UMR_7583) - Laboratoire Interuniversitaire des Systèmes Atmosphériques
3 SATINV - Modélisation INVerse pour les mesures atmosphériques et SATellitaires
4 ECOSYS - Ecologie fonctionnelle et écotoxicologie des agroécosystèmes
5 INERIS - Institut National de l'Environnement Industriel et des Risques
6 SQUARES - Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing
7 TROPO - LATMOS

Agriculture is the main source of ammonia (NH3) in France, an important gaseous precursor of atmospheric particulate matter (PM). National and even more global emission inventories are known to have difficulty representing the large spatial and temporal variability inherent to atmospheric NH3. In this study, we compare NH3 emissions in France during the spring 2011 from (i) one reference inventory, the TNO inventory, and two alternative inventories that account in different manners for both the spatial and temporal variabilities of the emissions (ii) the NH3SAT satellite-derived inventory based on IASI NH3 columns and (iii) the CADASTRE-CIT inventory that combines NH3 emissions due to nitrogen fertilization calculated with the mechanistic model VOLT'AIR on the database of the CADASTRE_NH3 framework and other source emissions from the CITEPA. The total spring budgets at the national level are higher when calculated with both alternative inventories than with the reference, the difference being more marked with CADASTRE-CIT. NH3SAT and CADASTRE-CIT inventories both yield to large NH3 emissions due to fertilization on soils with high pH in the northeastern part of France (65 kt NH3 and 135 kt NH3, respectively, vs 48 kt NH3 for TNO-GEN), while soil properties are not accounted for by the TNO-GEN methodology. For the other parts of France, the differences are smaller. The timing of fertilization and associated ammonia emissions is closely related to the nitrogen requirements and hence the phenological stage of the crops, and therefore tothe crop-year's specific weather conditions. Maximum emissions are observed in March for 2011 for some regions for both alternative inventories, while April is the period with maximum emissions for the reference inventory whatever the region or the year. Comparing the inventories at finer temporal resolutions, typically at daily scale, large differences are found. The convergence of alternative, independent and complementary methods on the spatiotemporal representation of the spring NH3 emissions particularly over areas where the contribution of mineral fertilizer spreading to the spring budget is strong, encouraging further developments in both prospected complementary directions, as this will help improving national NH3 emission inventories.

Domaines: Sciences de l'environnement

Audrey Fortems-Cheiney, Gaelle Dufour, Karine Dufossé, Florian Couvidat, Jean-Marc Gilliot, et al.. Do alternative inventories converge on the spatiotemporal representation of spring ammonia emissions in France?. Atmospheric Chemistry and Physics, 2020, 20 (21), pp.13481-13495. ⟨10.5194/acp-20-13481-2020⟩. ⟨insu-02563240⟩