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| Titel |
Dry deposition fluxes and deposition velocities of seven trace metal species at five sites in central Taiwan – a summary of surrogate surface measurements and a comparison with model estimations |
| VerfasserIn |
L. Zhang, G. C. Fang, C. K. Liu, Y. L. Huang, J. H. Huang, C. S. Huang |
| 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 ; 12, no. 7 ; Nr. 12, no. 7 (2012-04-11), S.3405-3417 |
| Datensatznummer |
250011019
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| Publikation (Nr.) |
 copernicus.org/acp-12-3405-2012.pdf |
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| Zusammenfassung |
| Daily air concentrations and dry deposition fluxes of
seven metal species were monitored at five sites in central Taiwan for five
or six days every month from September 2009 to August 2010. Annual average
concentrations at the five sites were in the range of 2.8 to 3.6 ng m−3
for As, 25 to 82 ng m−3 for Mn, 1900 to 2800 ng m−3 for Fe, 69
to 109 ng m−3 for Zn, 18 to 33 ng m−3 for Cr, 60 to 110 ng m−3
for Cu, and 25 to 40 ng m−3 for Pb. Annual average dry
deposition fluxes were on the order of 3, 20, 400, 50, 25, 50, and 50 μg m−2 day−1
for As, Mn, Fe, Zn, Cr, Cu, and Pb, respectively.
Annual average dry deposition velocities (Vd) for the seven metal
species ranged from 0.18 to 2.22 cm s−1 at these locations. Small
seasonal and geographical variations, e.g. from a few percent to a factor
of 2 for different species and/or at different locations, were found in the
measured concentrations, fluxes, and Vds. The measured fluxes and air
concentrations had moderate to good correlations for several of the species
at several of the sites (e.g. Fe, Zn, and Mn at most of the sites), but had
either weak or no correlations for the other species or at the other sites
(e.g. As at Sites I and III, Zn and Cr at Site IV, and Cu at most of the
sites). The latter cases were believed to have large uncertainties in the
flux measurements using surrogate surfaces. Sensitivity tests were conducted
for particle Vds using a size-segregated particle dry deposition model,
assuming various combinations of three lognormal size distributions
representing fine particles (PM2.5), coarse particles (PM2.5–10),
and super-sized particles (PM10+), respectively. It was found that the
measured dry deposition fluxes can be reproduced reasonably well using the
size-segregated particle dry deposition model if the mass fractions of the
metal species in PM2.5, PM2.5–10 and PM10+ were known.
Significant correlations between the modeled and the measured daily fluxes
were found for those cases that were believed to have small uncertainties in
the flux measurements. |
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