1Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, 82234 Wessling, Germany
2School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester M13 9PL, UK
3Leibniz-Institut für Troposphärenforschung, 04318 Leipzig, Germany
4School of Physics and Centre for Climate & Air Pollution Studies (C-CAPS), Environmental Change Institute (ECI), National University of Ireland, Galway, Ireland
5Hohenpeissenberg Meteorological Observatory, German Meteorological Service, 82383 Hohenpeissenberg, Germany
6TNO, Utrecht, The Netherlands
7Department of Physics, P.O. Box 64, 00014 University of Helsinki, Finland
8Division of Nuclear Physics, Department of Physics, Lund University, P.O. Box 118, 221 00 Lund, Sweden
9Finnish Meteorological Institute, Climate Change Unit, P.O. Box 503, 00101 Helsinki, Finland
10Norwegian Institute for Air Research (NILU), P.O. Box 100, 2027 Kjeller, Norway
11School of Engineering, University of California Merced (UCM), 5200 North Lake Rd., Merced, CA 95343, USA
12Department of Applied Environmental Science (ITM), Stockholm University, 10691 Stockholm, Sweden
Abstract. The European integrated project on Aerosol Cloud Climate and Air Quality Interactions (EUCAARI) focuses on understanding the interactions of climate and air pollution. As part of the EUCAARI intensive observational period, an aircraft field campaign (EUCAARI-LONGREX) was conducted in May 2008. The campaign aimed at studying the distribution and evolution of air mass properties on a continental scale. Airborne aerosol and trace gas measurements were performed aboard the German DLR Falcon 20 and the British FAAM BAe-146 aircraft. This paper outlines the meteorological situation over Europe during May 2008 and the temporal and spatial evolution of predominantly anthropogenic particulate pollution inside the boundary layer and the free troposphere. Time series data of six selected ground stations are used to discuss continuous measurements besides the single flights. The observations encompass total and accumulation mode particle number concentration (0.1–0.8 μm) and black carbon mass concentration as well as several meteorological parameters. Vertical profiles of total aerosol number concentration up to 10 km are compared to vertical profiles probed during previous studies.
During the first half of May 2008 an anticyclonic blocking event dominated the weather over Central Europe. It led to increased pollutant concentrations within the centre of the high pressure inside the boundary layer. Due to long-range transport the accumulated pollution was partly advected towards Western and Northern Europe. The measured aerosol number concentrations over Central Europe showed in the boundary layer high values up to 14 000 cm−3 for particles in diameter larger 10 nm and 2300 cm−3 for accumulation mode particles during the high pressure period, whereas the middle free troposphere showed rather low concentrations of particulates. Thus a strong negative gradient of aerosol concentrations between the well mixed boundary layer and the clean middle troposphere occurred.