Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia
This paper presents the first gaseous elemental mercury (GEM) air-surface exchange measurements obtained over naturally enriched and background (<0.1 μg g<sup>−1</sup> Hg) terrestrial landscapes in Australia. Two pilot field studies were carried out during the Australian autumn and wi...
Main Authors: | , |
---|---|
Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2013-05-01
|
Series: | Atmospheric Chemistry and Physics |
Online Access: | http://www.atmos-chem-phys.net/13/5325/2013/acp-13-5325-2013.pdf |
id |
doaj-bf7847dddc7b4c6a8eb37d5fb6886ad8 |
---|---|
record_format |
Article |
spelling |
doaj-bf7847dddc7b4c6a8eb37d5fb6886ad82020-11-24T23:23:01ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242013-05-0113105325533610.5194/acp-13-5325-2013Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in AustraliaG. C. EdwardsD. A. HowardThis paper presents the first gaseous elemental mercury (GEM) air-surface exchange measurements obtained over naturally enriched and background (<0.1 μg g<sup>−1</sup> 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<sup>−2</sup> h<sup>−1</sup> to 113 ± 6 ng m<sup>−2</sup> h<sup>−1</sup>. 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<sup>−2</sup> h<sup>−1</sup>. 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<sup>−1</sup> to 0.0083 cm s<sup>−1</sup> with an average of 0.0041 ± 0.00018 cm s<sup>−1</sup>, 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.http://www.atmos-chem-phys.net/13/5325/2013/acp-13-5325-2013.pdf |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
G. C. Edwards D. A. Howard |
spellingShingle |
G. C. Edwards D. A. Howard Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia Atmospheric Chemistry and Physics |
author_facet |
G. C. Edwards D. A. Howard |
author_sort |
G. C. Edwards |
title |
Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia |
title_short |
Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia |
title_full |
Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia |
title_fullStr |
Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia |
title_full_unstemmed |
Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia |
title_sort |
air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in australia |
publisher |
Copernicus Publications |
series |
Atmospheric Chemistry and Physics |
issn |
1680-7316 1680-7324 |
publishDate |
2013-05-01 |
description |
This paper presents the first gaseous elemental mercury (GEM) air-surface exchange measurements obtained over naturally enriched and background (<0.1 μg g<sup>−1</sup> 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<sup>−2</sup> h<sup>−1</sup> to 113 ± 6 ng m<sup>−2</sup> h<sup>−1</sup>. 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<sup>−2</sup> h<sup>−1</sup>. 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<sup>−1</sup> to 0.0083 cm s<sup>−1</sup> with an average of 0.0041 ± 0.00018 cm s<sup>−1</sup>, 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. |
url |
http://www.atmos-chem-phys.net/13/5325/2013/acp-13-5325-2013.pdf |
work_keys_str_mv |
AT gcedwards airsurfaceexchangemeasurementsofgaseouselementalmercuryovernaturallyenrichedandbackgroundterrestriallandscapesinaustralia AT dahoward airsurfaceexchangemeasurementsofgaseouselementalmercuryovernaturallyenrichedandbackgroundterrestriallandscapesinaustralia |
_version_ |
1725565893469011968 |