Airborne observation of mixing across the entrainment zone during PARADE 2011
- 1Institute for Atmospheric Physics, Johannes Gutenberg University Mainz, Mainz, Germany
- 2Department of Atmospheric Chemistry, Max Planck Institute for Chemistry, Mainz, Germany
- 3Institute for Atmospheric and Climate Science, ETH Zurich, Zürich, Switzerland
- 4Empa Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
- anow at: Institute of Energy and Climate Research-8: Troposphere, Forschungszentrum Jülich GmbH, Jülich, Germany
Abstract. This study presents the analysis of the structure and air mass characteristics of the lower atmosphere during the field campaign PARADE (PArticles and RAdicals: Diel observations of the impact of urban and biogenic Emissions) on Mount Kleiner Feldberg in southwestern Germany during late summer 2011. We analysed measurements of meteorological variables (temperature, moisture, pressure, wind speed and direction) from radio soundings and of chemical tracers (carbon dioxide, ozone) from aircraft measurements. We focus on the thermodynamic and dynamic properties that control the chemical distribution of atmospheric constituents in the boundary layer. We show that the evolution of tracer profiles of CO2 and O3 indicate mixing across the inversion layer (or entrainment zone). This finding is supported by the analysis of tracer–tracer correlations which are indicative for mixing and the relation of tracer profiles in relation to the evolution of the boundary layer height deduced from radio soundings. The study shows the relevance of entrainment processes for the lower troposphere in general and specifically that the tracer–tracer correlation method can be used to identify mixing and irreversible exchange processes across the inversion layer.