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| Titel |
Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia |
| VerfasserIn |
G. C. Edwards, D. A. Howard |
| 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 ; 13, no. 10 ; Nr. 13, no. 10 (2013-05-27), S.5325-5336 |
| Datensatznummer |
250018674
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| Publikation (Nr.) |
 copernicus.org/acp-13-5325-2013.pdf |
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| Zusammenfassung |
| This paper presents the first gaseous elemental mercury (GEM) air-surface
exchange measurements obtained over naturally enriched and background
(<0.1 μg g−1 Hg) terrestrial landscapes in
Australia. Two pilot field studies were carried out during the Australian
autumn and winter periods at a copper-gold-cobalt-arsenic-mercury mineral
field near Pulganbar, NSW. GEM fluxes using a dynamic flux chamber approach
were measured, along with controlling environmental parameters over three
naturally enriched and three background substrates. The enriched sites
results showed net emission to the atmosphere and a strong correlation
between flux and substrate Hg concentration, with average fluxes ranging from
14 ± 1 ng m−2 h−1 to 113 ± 6 ng m−2 h−1.
Measurements at background sites showed both emission and deposition. The
average Hg flux from all background sites showed an overall net emission of
0.36 ± 0.06 ng m−2 h−1. Fluxes show strong relationships
with temperature, radiation, and substrate parameters. A compensation point
of 2.48, representative of bare soils was determined. For periods of
deposition, dry deposition velocities ranged from 0.00025 cm s−1 to
0.0083 cm s−1 with an average of 0.0041 ± 0.00018 cm s−1,
representing bare soil, nighttime conditions. Comparison of the Australian
data to North American data suggests the need for Australian-specific mercury
air-surface exchange data representative of Australia's unique climatic
conditions, vegetation types, land use patterns and soils. |
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