 |
| Titel |
Connections between atmospheric sulphuric acid and new particle formation during QUEST III-IV campaigns in Heidelberg and Hyytiälä |
| VerfasserIn |
I. Riipinen, S.-L. Sihto, M. Kulmala  , F. Arnold, M. Maso, W. Birmili, K. Saarnio, K. Teinilä, V.-M. Kerminen, A. Laaksonen, K. E. J. Lehtinen |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 7, no. 8 ; Nr. 7, no. 8 (2007-04-17), S.1899-1914 |
| Datensatznummer |
250004906
|
| Publikation (Nr.) |
 copernicus.org/acp-7-1899-2007.pdf |
|
|
|
|
|
| Zusammenfassung |
| This study investigates the connections between atmospheric
sulphuric acid and new particle formation during QUEST III and
BACCI/QUEST IV campaigns. The campaigns have been conducted in
Heidelberg (2004) and Hyytiälä (2005), the first
representing a polluted site surrounded by deciduous forest, and
the second a rural site in a boreal forest environment. We have
studied the role of sulphuric acid in particle formation and
growth by determining 1) the power-law dependencies between
sulphuric acid ([H2SO4]), and particle concentrations
(N3–6) or formation rates at 1 nm and 3 nm (J1 and
J3); 2) the time delays between [H2SO4] and
N3–6 or J3, and the growth rates for 1–3 nm particles;
3) the empirical nucleation coefficients A and K in relations
J1=A[H2SO4] and
J1=K[H2SO4]2, respectively; 4) theoretical
predictions for J1 and J3 for the days when no
significant particle formation is observed, based on the observed
sulphuric acid concentrations and condensation sinks. In both
environments, N3–6 or J3 and [H2SO4] were
linked via a power-law relation with exponents typically ranging
from 1 to 2. The result suggests that the cluster activation
theory and kinetic nucleation have the potential to explain the
observed particle formation. However, some differences between the
sites existed: The nucleation coefficients were about an order of
magnitude greater in Heidelberg than in Hyytiälä
conditions. The time lags between J3 and [H2SO4]
were consistently lower than the corresponding delays between
N3–6 and [H2SO4]. The exponents in
the J3∝[H2SO4 ]nJ3-connection were
consistently higher than or equal to the exponents in the relation
N3–6∝[H2SO4 ]nN36. In the
J1 values, no significant differences were found between the
observed rates on particle formation event days and the
predictions on non-event days. The J3 values predicted by the
cluster activation or kinetic nucleation hypotheses, on the other
hand, were considerably lower on non-event days than the rates
observed on particle formation event days. This study provides
clear evidence implying that the main process limiting the
observable particle formation is the competition between the
growth of the freshly formed particles and their loss by
scavenging, rather than the initial particle production by
nucleation of sulphuric acid. In general, it can be concluded that
the simple models based on sulphuric acid concentrations and
particle formation by cluster activation or kinetic nucleation can
predict the occurence of atmospheric particle formation and growth
well, if the particle scavenging is accurately accounted for. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|