Overview of EURODELTA-TRENDS, the air quality Hindcast modelling exercise
Résumé
A multi-model exercise has been set up by the Task Force on Measurement and Modelling of the Convention on Long-Range Transboundary of Air Pollution in order to assess the evolution of air quality in Europe since the early 1990s. The main science and policy question addressed by the exercise is to assess the efficiency of emission mitigation measures in improving the air quality at the continental scale. It is also expected that EURODELTA-TRENDS will better quantify (i) the capability of models (and underlying emission inventories) in simulating the long term evolution of air quality, (ii) the importance of intercontinental transport of air pollution through the boundary conditions of the regional models, (iii) the role of interannual meteorological variability. In order to cover a range of uncertainty, in addition to the model being used in support to the Convention (EMEP/MSC-W), six chemistry transport models participated to the exercise: Chimere, CMAQ, LOTOS-EUROS, MINNI, Polyphemus and WRF-CHEM. The modelling experiment is organised in three tiers: (i) a reference for the years 1990, 2000 and 2010, including also sensitivity simulations devoted to emission changes, (ii) six sensitivity simulations for boundary condition changes, (iii) full modelling of the complete 21-yr time series for 1990 to 2010. An overview of the experiment will be given as well as key results in terms of (i) trend modelling benchmarking and (ii) attribution of the main factors underlying the evolution over the past 20 years of particulate matter, ozone, and also acidifying and eutrophying pollution in Europe.