Influence of the North Atlantic Oscillation on air pollution transport T. Christoudias1, A. Pozzer2,3,*, and J. Lelieveld2,3,4 1Computation-based Science and Technology Research Center, The Cyprus Institute, Nicosia, Cyprus 2Energy, Environment and Water Research Center, The Cyprus Institute, Nicosia, Cyprus 3Air Chemistry Department, Max Planck Institute of Chemistry, Mainz, Germany 4King Saud University, Riyadh, Saudi Arabia *now at: Abdus Salam International Center for Theoretical Physics, Earth System Physics, Trieste, Italy
Abstract. We examined the influence of the North Atlantic Oscillation (NAO) on the
atmospheric dispersion of pollution by computing the emission, transport and
removal of idealized insoluble gaseous and water-soluble aerosol tracers, tagged by the
continent of origin. We simulated a period of 50 yr (1960–2010), using the
ECHAM5/MESSy1 atmospheric chemistry (EMAC) general circulation model. The model
accounts for anthropogenic, biogenic and biomass burning sources, removal of
trace gases through OH oxidation, and precipitation, sedimentation and
deposition of aerosols. The model is shown to reproduce the observed spatial
features of the NAO, moisture transports and precipitation. During high NAO
phase seasons the axis of maximum westerly North American trace gas
transports extends relatively far to the north and east over Europe. The NAO
phase is significantly correlated with North American
insoluble gas and soluble aerosol tracer concentrations
over the northwestern Atlantic Ocean and across northern Europe, and with
European trace gases and aerosols over Africa and north of the Arctic circle.
We find a strong anti-correlation between the phase of the NAO
and European pollutant gas concentration over western and central Europe.
Citation: Christoudias, T., Pozzer, A., and Lelieveld, J.: Influence of the North Atlantic Oscillation on air pollution transport, Atmos. Chem. Phys., 12, 869-877, doi:10.5194/acp-12-869-2012, 2012.