Exploitable results Measurement and modelling of the exchange of atmospheric ammonia with ecosystems Ammonia is a trace gas that is important for atmospheric chemistry and biospheric-processes of ecosystems. It contributes to both soil acidification and eutrophication, which may alter ecosystem species composition and productivity. The EXAMINE project has provided measurements and modelling leading to an improved understanding and quantification of the ecosystem-atmosphere exchange of ammonia. This information is necessary to provide the scientific underpinning of European Union (EU) environmental policy, particularly the EU Acidification Strategy, the UNECE Nitrogen Protocol, and the IPPC Directive in the agricultural sector. The developed models fall into 4 groups: application of inverse-Lagrangian theory to model the sources and sinks of ammonia within plant canopies; gas to particle conversion models for ammonia surface-atmosphere exchange; one-layer canopy compensation point resistance models of ammonia exchange with ecosystems; multi-layer canopy compensation point resistance models of ammonia exchange. The one-layer models have been applied to provide the first general bi-directional resistance modelling of ammonia exchange over Europe, using a version of the European Monitoring and Evaluation Programme (EMEP) model. These developments will help underpin EU policy through: improved quantification of deposition and critical loads exceedances; improved assessment of the transport distance of ammonia; the ability of the models to consider the response of ammonia exchange to climate change; more reliable descriptions of dry deposition near ammonia sources; and the ability of the models to consider the impact of ammonia exchange on aerosol production. Searching for OpenAIRE data... There was an error trying to search data from OpenAIRE No results available
