A case of extreme particulate matter concentrations over Central Europe caused by dust emitted over the southern Ukraine W. Birmili1, K. Schepanski1,2, A. Ansmann1, G. Spindler1, I. Tegen1, B. Wehner1, A. Nowak1, E. Reimer3, I. Mattis1, K. Müller1, E. Brüggemann1, T. Gnauk1, H. Herrmann1, A. Wiedensohler1, D. Althausen1, A. Schladitz1, T. Tuch1,4, and G. Löschau5 1Leibniz Institute for Tropospheric Research, Leipzig, Germany 2Leibniz Institute of Marine Sciences, IFM-GEOMAR, Kiel, Germany 3Institut für Meteorologie, Freie Universität Berlin, Germany 4Helmholtz Center for Environmental Research, Leipzig, Germany 5Sächsisches Landesamt für Umwelt und Geologie, Dresden, Germany
Abstract. On 24 March 2007, an extraordinary dust plume was observed in the Central European troposphere.
Satellite observations revealed its origins in a dust storm in Southern Ukraine, where large
amounts of soil were resuspended from dried-out farmlands at wind gusts up to 30 m s−1.
Along the pathway of the plume, maximum particulate matter (PM10) mass concentrations between
200 and 1400 μg m−3 occurred in Slovakia, the Czech Republic, Poland, and Germany. Over
Germany, the dust plume was characterised by a volume extinction coefficient up to 400 Mm−1
and a particle optical depth of 0.71 at wavelength 0.532 μm. In-situ size distribution
measurements as well as the wavelength dependence of light extinction from lidar and Sun photometer
measurements confirmed the presence of a coarse particle mode with diameters around 2–3 μm.
Chemical particle analyses suggested a fraction of 75% crustal material in daily average
PM10 and up to 85% in the coarser fraction PM10–2.5. Based on the particle
characteristics as well as a lack of increased CO and CO2 levels, a significant
impact of biomass burning was ruled out. The reasons for the high particle concentrations in the
dust plume were twofold: First, dust was transported very rapidly into Central Europe in a boundary
layer jet under dry conditions. Second, the dust plume was confined to a relatively stable boundary
layer of 1.4–1.8 km height, and could therefore neither expand nor dilute efficiently. Our
findings illustrate the capacity of combined in situ and remote sensing measurements to
characterise large-scale dust plumes with a variety of aerosol parameters. Although such plumes
from Southern Eurasia seem to occur rather infrequently in Central Europe, its unexpected features
highlights the need to improve the description of dust emission, transport and transformation
processes needs, particularly when facing the possible effects of further anthropogenic
desertification and climate change.
Citation: Birmili, W., Schepanski, K., Ansmann, A., Spindler, G., Tegen, I., Wehner, B., Nowak, A., Reimer, E., Mattis, I., Müller, K., Brüggemann, E., Gnauk, T., Herrmann, H., Wiedensohler, A., Althausen, D., Schladitz, A., Tuch, T., and Löschau, G.: A case of extreme particulate matter concentrations over Central Europe caused by dust emitted over the southern Ukraine, Atmos. Chem. Phys., 8, 997-1016, doi:10.5194/acp-8-997-2008, 2008.