Abstract : B.1
Distribution of air pollutants in an Alpine boundary layer during winter

Johannes Vergeiner, Stefan Emeis, Esther Griesser, Friedrich Obleitner, Martin Staszewski, Klaus Schäfer
Institute of Meteorology and Geophysics, University of Innsbruck

We study the vertical and horizontal distribution of air pollutants and its connection to stability in the boundary layer of the Austrian Inn valley. The analyses are based on data gathered during a field experiment in winter 2005/ 2006 performed in the framework of the Alpine Space project ALPNAP. The focus is on the comparison and synopsis of information from different measurement systems during selected days of interest. The devices include a meteorological sonde and fine dust monitor on a tethered balloon as well as mobile car measurements during selected episodes, a sodar and a ceilometer giving information on the vertical distribution of wind and aerosol parameters. Furthermore a temperature profile consisting of eight sensors along the southern slopes, automated weather stations and air pollution measurement devices - mainly monitoring nitrogen oxides and fine dust.

Of specific interest are the differences between mid-valley conditions (as captured by the tethered balloon system) and slope conditions (recorded by the car platform, ground-based stations and the temperature profile). Another topic will be the connection of stability, wind and turbulence information to the vertical distribution of air pollutants, mainly particulate matter and nitrogen oxides. Different methods of estimating the mixing layer height directly or the location of the lowest layer inhibiting the vertical exchange of air masses are compared. Also the usefulness of the permanently installed temperature profile is discussed in this context, considering slope effects as well as local influences.