Articles | Volume 16, issue 12
Atmos. Chem. Phys., 16, 7785–7811, 2016
Atmos. Chem. Phys., 16, 7785–7811, 2016

Research article 24 Jun 2016

Research article | 24 Jun 2016

BAERLIN2014 – the influence of land surface types on and the horizontal heterogeneity of air pollutant levels in Berlin

Boris Bonn1,a, Erika von Schneidemesser1, Dorota Andrich1,b, Jörn Quedenau1, Holger Gerwig2, Anja Lüdecke2, Jürgen Kura2, Axel Pietsch2, Christian Ehlers3, Dieter Klemp3, Claudia Kofahl3, Rainer Nothard4, Andreas Kerschbaumer4, Wolfgang Junkermann5, Rüdiger Grote5, Tobias Pohl6, Konradin Weber6, Birgit Lode1, Philipp Schönberger1, Galina Churkina1, Tim M. Butler1, and Mark G. Lawrence1 Boris Bonn et al.
  • 1Institute for Advanced Sustainability Studies (IASS), 14467 Potsdam, Germany
  • 2Division Environmental Health and Protection of Ecosystems, German Environment Agency, 06844 Dessau-Roßlau, Germany
  • 3IEK-8, Research Centre Jülich, 52425 Jülich, Germany
  • 4Senate Department for Urban Development and the Environment, 10179 Berlin, Germany
  • 5Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research, Atmospheric Environmental Research (IMK-IFU), Campus Alpin, 82467 Garmisch-Partenkirchen, Germany
  • 6Environmental Measurement Techniques, University of Applied Sciences, 40474 Düsseldorf, Germany
  • anow at: Institute for Forest Sciences, Albert-Ludwig University, 79110 Freiburg, Germany
  • bnow at: Andritz AG, Graz, Austria

Abstract. Urban air quality and human health are among the key aspects of future urban planning. In order to address pollutants such as ozone and particulate matter, efforts need to be made to quantify and reduce their concentrations. One important aspect in understanding urban air quality is the influence of urban vegetation which may act as both emitter and sink for trace gases and aerosol particles. In this context, the "Berlin Air quality and Ecosystem Research: Local and long-range Impact of anthropogenic and Natural hydrocarbons 2014" (BAERLIN2014) campaign was conducted between 2 June and 29 August in the metropolitan area of Berlin and Brandenburg, Germany. The predominant goals of the campaign were (1) the characterization of urban gaseous and particulate pollution and its attribution to anthropogenic and natural sources in the region of interest, especially considering the connection between biogenic volatile organic compounds and particulates and ozone; (2) the quantification of the impact of urban vegetation on organic trace gas levels and the presence of oxidants such as ozone; and (3) to explain the local heterogeneity of pollutants by defining the distribution of sources and sinks relevant for the interpretation of model simulations. In order to do so, the campaign included stationary measurements at urban background station and mobile observations carried out from bicycle, van and airborne platforms. This paper provides an overview of the mobile measurements (Mobile BAERLIN2014) and general conclusions drawn from the analysis. Bicycle measurements showed micro-scale variations of temperature and particulate matter, displaying a substantial reduction of mean temperatures and particulate levels in the proximity of vegetated areas compared to typical urban residential area (background) measurements. Van measurements extended the area covered by bicycle observations and included continuous measurements of O3, NOx, CO, CO2 and point-wise measurement of volatile organic compounds (VOCs) at representative sites for traffic- and vegetation-affected sites. The quantification displayed notable horizontal heterogeneity of the short-lived gases and particle number concentrations. For example, baseline concentrations of the traffic-related chemical species CO and NO varied on average by up to ±22.2 and ±63.5 %, respectively, on the scale of 100 m around any measurement location. Airborne observations revealed the dominant source of elevated urban particulate number and mass concentrations being local, i.e., not being caused by long-range transport. Surface-based observations related these two parameters predominantly to traffic sources. Vegetated areas lowered the pollutant concentrations substantially with ozone being reduced most by coniferous forests, which is most likely caused by their reactive biogenic VOC emissions. With respect to the overall potential to reduce air pollutant levels, forests were found to result in the largest decrease, followed by parks and facilities for sports and leisure. Surface temperature was generally 0.6–2.1 °C lower in vegetated regions, which in turn will have an impact on tropospheric chemical processes. Based on our findings, effective future mitigation activities to provide a more sustainable and healthier urban environment should focus predominantly on reducing fossil-fuel emissions from traffic as well as on increasing vegetated areas.

Short summary
The distribution of air pollutants (gases and particles) have been investigated in different environments in Potsdam, Germany. Remarkable variations of the pollutants have been observed for distances of tens of meters by bicycles, vans and aircraft. Vegetated areas caused reductions depending on the pollutants, the vegetation type and dimensions. Our measurements show the pollutants to be of predominantly local origin, resulting in a huge challenge for common models to resolve.
Final-revised paper