title: Simulated air quality and pollutant budgets over Europe in 2008.
abstract: Major gaseous and particulate pollutant levels over Europe in 2008 have been simulated using the offline-coupled WRFCMAQ chemistry and transport modeling system. The simulations are compared with surface observations from the EMEP stations, ozone (O3) soundings, ship-borne O3 and nitrogen dioxide (NO2) observations in the western Mediterranean, tropospheric NO2 vertical column densities from the SCIAMACHY instrument, and aerosol optical depths (AOD) from the AERONET. The results show that on average, surface O3 levels are underestimated by 4 to 7% over the northern European EMEP stations while they are overestimated by 7-10% over the southern European EMEP stations and underestimated in the tropospheric column (by 10-20%). Particulate matter (PM) mass concentrations are underestimated by up to 60%, particularly in southern and eastern Europe, suggesting underestimated PM sources. Larger differences are calculated for individual aerosol components, particularly for organic and elemental carbon than for the total PM mass, indicating uncertainty in the combustion sources. Better agreement has been obtained for aerosol species over urban areas of the eastern Mediterranean, particularly for nss-SO4(2), attributed to the implementation of higher quality emission inventories for that area. Simulated AOD levels are lower than the AERONET observations by 10% on average, with average underestimations of 3% north of 40°N, attributed to the low anthropogenic emissions in the model and 22% south of 40°N, suggesting underestimated natural and resuspended dust emissions. Overall, the results reveal differences in the model performance between northern and southern Europe, suggesting significant differences in the representation of both anthropogenic and natural emissions in these regions. Budget analyses indicate that O3 and peroxyacetyl nitrate (PAN) are transported from the free troposphere (FT) to the planetary boundary layer over Europe, while other species follow the reverse path and are then advected away from the source region.
authors.affiliation: Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, Heraklion, Greece; Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas (FORTH/ICE-HT), Patras, Greece.
authors.forename: U
authors.initials: U
authors.lastname: Im
authors.affiliation: Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, Heraklion, Greece; Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas (FORTH/ICE-HT), Patras, Greece.
authors.forename: N
authors.initials: N
authors.lastname: Daskalakis
authors.affiliation: Laboratoire de Meteorologie Dynamique (LMD), IPSL Ecole Polytechnique, Palaiseau Cedex, Paris, France.
authors.forename: K
authors.initials: K
authors.lastname: Markakis
authors.affiliation: Energy, Environment and Water Research Center, The Cyprus Institute, Nicosia, Cyprus; Academy of Athens, Athens, Greece.
authors.forename: M
authors.initials: M
authors.lastname: Vrekoussis
authors.affiliation: Air and Climate Unit, Joint Research Centre, Ispra, Italy.
authors.forename: J
authors.initials: J
authors.lastname: Hjorth
authors.affiliation: Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, Heraklion, Greece.
authors.forename: S
authors.initials: S
authors.lastname: Myriokefalitakis
authors.affiliation: Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Athens, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Gerasopoulos
authors.affiliation: Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, Heraklion, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Kouvarakis
authors.affiliation: Institute of Environmental Physics, University of Bremen, Bremen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Richter
authors.affiliation: Institute of Environmental Physics, University of Bremen, Bremen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Burrows
authors.affiliation: Eurasia Institute of Earth Sciences, Istanbul Technical University, Istanbul, Turkey.
authors.forename: L
authors.initials: L
authors.lastname: Pozzoli
authors.affiliation: Eurasia Institute of Earth Sciences, Istanbul Technical University, Istanbul, Turkey.
authors.forename: A
authors.initials: A
authors.lastname: Unal
authors.affiliation: Eurasia Institute of Earth Sciences, Istanbul Technical University, Istanbul, Turkey.
authors.forename: T
authors.initials: T
authors.lastname: Kindap
authors.affiliation: Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, Heraklion, Greece. Electronic address: mariak@chemistry.uoc.gr.
authors.forename: M
authors.initials: M
authors.lastname: Kanakidou
mesh_terms: D000397:Air Pollution / Q000706:statistics & numerical data*; D004784:Environmental Monitoring; D005060:Europe; D008956:Models, Chemical
keywords: AOD; Aerosols; Emission distributions; Europe; North–south gradient; Ozone