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| Titel |
Aerosols and nucleation in eastern China: first insights from the new SORPES-NJU station |
| VerfasserIn |
E. Herrmann, A. J. Ding, V.-M. Kerminen, T. Petäjä, X. Q. Yang, J. N. Sun, X. M. Qi, H. Manninen, J. Hakala, T. Nieminen, P. P. Aalto, M. Kulmala  , C. B. Fu |
| 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 ; 14, no. 4 ; Nr. 14, no. 4 (2014-02-27), S.2169-2183 |
| Datensatznummer |
250118428
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| Publikation (Nr.) |
 copernicus.org/acp-14-2169-2014.pdf |
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| Zusammenfassung |
| Aerosols and new particle formation were studied in the western part of the
Yangtze River Delta (YRD) at the Station for Observing Regional Processes of
the Earth System, Nanjing University (SORPES-NJU). Air ions in the diameter
range 0.8–42 nm were measured using an air ion spectrometer, and a
differential mobility particle sizer (DMPS) provided particle number size
distributions between 6 and 800 nm. Additionally, meteorological data, trace
gas concentrations, and PM2.5 values were recorded. During the
measurement period from 18 November 2011 to 31 March 2012, the mean total
particle concentration was found to be 23 000 cm−3 and the mean
PM2.5 value was 90 μg m−3, well above national limits.
We observed 26 new particle formation events occurred during the measurement
period, producing 6 nm particles at a rate of about 1 cm−3 s−1.
Typical particle growth rates were between 6 and 7 nm h−1. On average,
new particle formation and growth were estimated to enhance cloud
condensation nuclei concentration by about a factor of two during these event
days. Ion measurements showed the typical cluster band below 2 nm, with total
ion concentrations between about 600 and 1000 cm−3. A peculiar feature
of the ion measurements were heightened ion cluster concentrations during the
nights before the event days. At 2 nm, the formation rate of charged
particles was only about 0.2% of the total rate, pointing towards an
only marginal role of ion-induced nucleation. Based on observations, a simple
empirical criterion was deducted to estimate particle formation probability.
Dominated by radiation and relative humidity, the criterion can predict the
occurrence of particle formation with a 90% accuracy. In a similar
fashion, a reasonably accurate estimate of particle formation rates was
derived. Combined, these parameters allow for a description of particle
formation based on a few basic measured variables. |
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