The contribution of sulphuric acid to atmospheric particle formation and growth: a comparison between boundary layers in Northern and Central Europe V. Fiedler1,2, M. Dal Maso2, M. Boy2, H. Aufmhoff1, J. Hoffmann1, T. Schuck1, W. Birmili3, M. Hanke1, J. Uecker1, F. Arnold1, and M. Kulmala2 1Max-Planck Inst. for Nuclear Physics, (MPIK), Atmospheric Physics Div., P.O. Box 103980, 69029 Heidelberg, Germany 2University of Helsinki, Dept. Physical Sciences, P. O. Box 64, FIN-00014 Univ. of Helsinki, Finland 3Leibniz Institute for Tropospheric Research, Permoserstr. 15, D-04318 Leipzig, Germany
Abstract. Atmospheric gaseous sulphuric acid was measured and its influence on particle formation and growth was
investigated building on aerosol data. The measurements were part of the EU-project QUEST and took place at two
different measurement sites in Northern and Central Europe (Hyytiälä, Finland, March-April 2003 and
Heidelberg, Germany, March-April 2004). From a comprehensive data set including sulphuric acid, particle number
size distributions and meteorological data, particle growth rates, particle formation rates and source rates of
condensable vapors were inferred. Growth rates were determined in two different ways, from particle size
distributions as well as from a so-called timeshift analysis. Moreover, correlations between sulphuric acid and
particle number concentration between 3 and 6 nm were examined and the influence of air masses of different
origin was investigated. Measured maximum concentrations of sulphuric acid were in the range from
1x106 to 16x106cm-3. The gaseous sulphuric acid lifetime with respect to
condensation on aerosol particles ranged from 2 to 33min in Hyytiälä and from 0.5 to 8 min in
Heidelberg. Most calculated values (growth rates, formation rates, vapor source rates) were considerably higher
in Central Europe (Heidelberg), due to the more polluted air and higher preexistent aerosol concentrations.
Close correlations between H2SO4 and nucleation mode particles (size range: 3-6 nm) were found on
most days at both sites. The percentage contribution of sulphuric acid to particle growth was below 10% at
both places and to initial growth below 20%. An air mass analysis indicated that at Heidelberg new particles
were formed predominantly in air advected from southwesterly directions.
Citation: Fiedler, V., Dal Maso, M., Boy, M., Aufmhoff, H., Hoffmann, J., Schuck, T., Birmili, W., Hanke, M., Uecker, J., Arnold, F., and Kulmala, M.: The contribution of sulphuric acid to atmospheric particle formation and growth: a comparison between boundary layers in Northern and Central Europe, Atmos. Chem. Phys., 5, 1773-1785, doi:10.5194/acp-5-1773-2005, 2005.