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| Titel |
Number Size distribution of Atmospheric Submicron Aerosols in Thirteen Sites across China |
| VerfasserIn |
Jianfei Peng, Min Hu, Zhibin Wang, Dingli Yue |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250083902
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| Zusammenfassung |
| Number concentration and size distribution (15-600nm) of atmospheric submicron aerosols
have been measured in thirteen sites across China during several campaigns from 2006 to
2011. All the sampling sites are categorized into four types, including five urban sites, four
suburban sites, three regional sites and two cruise measurements along the eastern coast of
China. Spatial and temporal variation of aerosols in nucleation mode (with particle diameter
between 15 and 25 nm), Aitken mode (with particle diameter between 25 and 90 nm) as well
as accumulation mode (with particle diameter between 90 and 600 nm) in all sites are
investigated. Particle number concentration in urban and suburban sites are 2-5 times higher
than in regional and sites and cruise measurements. Higher concentration of nucleation mode
particles as well as more new particle formation events are found in urban and suburban
sites than in regional sites and cruise measurements, indicating high formation
rates in the urban sites due to anthropogenic emission of new particles formation
precursors. Aitken mode particles are abundant in both urban sites and suburban sites,
with larger variation in urban sites than in suburban sites. Accumulation mode
particles present higher concentration in winter than in summer. Diurnal trend of both
Aitken and accumulation mode shows a bimodal pattern, while the pattern of Aitken
mode particles is much more obvious in urban sites but can be barely found in
cruise measurements. Particle concentration in accumulation mode and Aitken
mode have a week correlation, with aerosols in different sites occupying different
Aitken/Accumulation region. Log-normal modal fitting treatment are also used on
particle size distribution data to provide the modal pattern as well as the aging
information. Particle size distribution shows bimodal or trimodal patterns in most cases in
urban sites. However, in regional sites and cruise measurements, the unimodal fit
can always do a good job. The median accumulation mode (with median diameter
larger than 70nm) diameters in suburban sites are often larger than those in urban
sites, suggesting the growth of particles owing to the aging processes during the
transportation. Rapid growth of median mode diameters are also found in urban sites
during certain pollution processes. Slight differences on particle size distribution
and diurnal variations among Beijing region, the Yangzi River Delta region and
the Pearl River Delta region are found and the correlative reasons are discussed. |
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