The contribution of sulphuric acid to atmospheric particle formation and growth: a comparison between boundary layers in Northern and Central Europe

Abstract

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 1×10 6 to 16×10 6 cm −3 . The gaseous sulphuric acid lifetime with respect to condensation on aerosol particles ranged from 2 to 33 min 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 H 2 SO 4 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.

Correlation of aerosol nucleation rate with sulfuric acid and ammonia in Kent, Ohio: An atmospheric observation

“…Therefore, indirect methods have been employed to estimate J of 1 nm cluster (J 1 ) from apparent nucleation rates (for example, J 3 which is the nucleation rate derived from particle concentrations in the size range >3 nm). The most commonly used method is based on the time shift (or time delay, Dt) by using the measured aerosol size distribution and by taking into account self-coagulation of small particles and scavenging due to coagulation with large particles [Dal Maso et al, 2005;Fiedler et al, 2005;Kerminen and Wexler, 1996;Kuang et al, 2008;Kulmala et al, 2004;Paasonen et al, 2009;Riipinen et al, 2007;Sihto et al, 2006;Stolzenberg et al, 2005;Weber et al, 1996]. In practice, H 2 SO 4 is considered as the aerosol precursor for this kind of time shift calculations, so by default this method also assumes that H 2 SO 4 is the only condensable species for aerosol formation.…”

“…More recent work from the same group, in collaboration with other colleagues, made in Atlanta, GA, Boulder, CO, Tecamac, Mexico, and Macquarie Island, Australia, have focused on the numerical relationship of nucleation rates (J) and [H 2 SO 4 ] [Kuang et al, 2008;McMurry and Eisele, 2005;. Longterm measurements of H 2 SO 4 have been made also in Europe, including Hyytiälä [Dal Maso et al, 2005;Fiedler et al, 2005;Sihto et al, 2006], Heidelberg [Fiedler et al, 2005] and Hohenpeissenberg [Birmili et al, 2000[Birmili et al, , 2003Paasonen et al, 2009]. These observations also showed that [H 2 SO 4 ] values typically were at the 10 6 -10 7 cm −3 range at noon, depending on the season.…”

“…[4] Atmospheric observations often showed that the observed nucleation rates are much higher than those predicted from the H 2 SO 4 -H 2 O binary homogeneous nucleation (BHN) theory and growth rates (GR) derived from H 2 SO 4 condensation are also much smaller than those derived from the measured aerosol size distributions [Birmili et al, 2003;Dal Maso et al, 2005;Fiedler et al, 2005;Kuang et al, 2008;Kulmala et al, 2004;Paasonen et al, 2009;Riipinen et al, 2007;Sihto et al, 2006;Stolzenberg et al, 2005;Weber et al, 1996]. GR is an important parameter which determines whether these newly formed nanometer size particles can effectively grow to cloud condensation nuclei sizes (>40 nm) before they are scavenged by preexisting particles.…”

Observations of New Particle Formation, Subsequent Growth and Shrinkage during Summertime in Beijing

“…If the concentration of H 2 SO 4 has been consumed in quantity, the NPF events would be interrupted. However, if sufficient concentrations of H 2 SO 4 were present in the atmosphere, nucleation could occur even under relatively high concentrations of preexisting particles (Fiedler et al, 2005). The production and concentration of H 2 SO 4 depend on the concentration of its precursors, SO 2 and OH (Mikkonen et al, 2011), where the OH concentration is dependent on the photolysis rate of O 3 by solar radiation in the 280-320-nm UVB range.…”

“…This process would be further enhanced with the increase of the concentration of preexisting particles; therefore, NPF would not occur in severely polluted environment. However if sufficient concentrations of precursors to begin NPF are present in the atmosphere, nucleation can occur even under relatively high background levels of pre-existing particles (Fiedler et al, 2005).…”