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| Titel |
Changes in the production rate of secondary aerosol particles in Central Europe in view of decreasing SO2 emissions between 1996 and 2006 |
| VerfasserIn |
A. Hamed, W. Birmili, J. Joutsensaari, S. Mikkonen, A. Asmi, B. Wehner, G. Spindler, A. Jaatinen, A. Wiedensohler, H. Korhonen, K. E. J. Lehtinen, A. Laaksonen |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 3 ; Nr. 10, no. 3 (2010-02-02), S.1071-1091 |
| Datensatznummer |
250008030
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| Publikation (Nr.) |
 copernicus.org/acp-10-1071-2010.pdf |
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| Zusammenfassung |
| In anthropogenically influenced atmospheres, sulphur dioxide (SO2) is
the main precursor of gaseous sulphuric acid (H2SO4), which in
turn is a main precursor for atmospheric particle nucleation. As a result of
socio-economic changes, East Germany has seen a dramatic decrease in
anthropogenic SO2 emissions between 1989 and present, as documented by
routine air quality measurements in many locations. We have attempted to
evaluate the influence of changing SO2 concentrations on the frequency
and intensity of new particle formation (NPF) using two different data sets
(1996–1997; 2003–2006) of experimental particle number size distributions
(diameter range 3–750 nm) from the atmospheric research station Melpitz near
Leipzig, Germany. Between the two periods SO2 concentrations decreased
by 65% on average, while the frequency of NPF events dropped by 45%.
Meanwhile, the average formation rate of 3 nm particles decreased by 68%
on average. The trends were statistically significant and therefore suggest
a connection between the availability of anthropogenic SO2 and freshly
formed new particles. In contrast to the decrease in new particle formation,
we found an increase in the mean growth rate of freshly nucleated particles
(+22%), suggesting that particle nucleation and subsequent growth into
larger sizes are delineated with respect to their precursor species. Using
three basic parameters, the condensation sink for H2SO4, the
SO2 concentration, and the global radiation intensity, we were able to
define the characteristic range of atmospheric conditions under which
particle formation events take place at the Melpitz site. While the decrease
in the concentrations and formation rates of the new particles was rather
evident, no similar decrease was found with respect to the generation of
cloud condensation nuclei (CCN; particle diameter >100 nm) as a result of
atmospheric nucleation events. On the contrary, the production of CCN following
nucleation events appears to have increased by tens of percents. Our aerosol
dynamics model simulations suggest that such an increase can be caused by the
increased particle growth rate. |
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