Influences of the 2010 Eyjafjallajökull volcanic plume on air quality in the northern Alpine region - Schäfer, K.; Thomas, W.; Peters, A.; Ries, L.; Obleitner, F.; Schnelle-Kreis, J.; Birmili, W.; Diemer, J.; Fricke, W.; Junkermann, W.; Pitz, M.; Emeis, S.; et al. (Atmos. Chem. Phys., 2011)