Particle formation at a continental background site: comparison of model results with observations U. Uhrner1, W. Birmili2, F. Stratmann3, M. Wilck3, I. J. Ackermann4, and H. Berresheim5 1Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, Germany 2Division of Environmental Health and Risk Management, Birmingham University, B15 2TT, UK 3Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, Germany 4Ford Research Centre Aachen, Süsterfeldstr. 200, 52072 Aachen, Germany 5German Weather Service – Deutscher Wetterdienst, Meteorological Observatory Hohenpeissenberg, Albin-Schwaiger-Weg 10, 83282 Hohenpeissenberg, Germany
Abstract. At Hohenpeissenberg
(47° 48' N, 11° 07' E, 988 m asl), a rural site 200--300~m higher than the surrounding terrain, sulphuric
acid concentrations, particle size distributions, and other trace gas concentrations were measured over a two and a half year
period. Measured particle number concentrations and inferred particle
surface area concentrations were compared with box-model simulations for 12 carefully selected data sets
collected during the HAFEX experiment (Birmili et al., 2003). The 12 cases
were selected after meteorological and aerosol dynamical criteria in order to justify the use of a box-model. The aerosol model
included a binary sulphuric acid water nucleation scheme. Calculated nucleation rates were corrected with a factor to match
measured and calculated particle number concentrations. For the investigated 12 data sets,
the correction factors were smallest for measurements made under stable thermal stratification and low wind conditions, i.e.
conditions that are frequently encountered during winter. Correction factors were largest for measurements made under strong
Our comparison of measured and simulated particle size distributions suggests that the particle formation process maybe
strongly influenced by mixing processes driven by thermal convection and/or wind sheer.
Citation: Uhrner, U., Birmili, W., Stratmann, F., Wilck, M., Ackermann, I. J., and Berresheim, H.: Particle formation at a continental background site: comparison of model results with observations, Atmos. Chem. Phys., 3, 347-359, doi:10.5194/acp-3-347-2003, 2003.