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| Titel |
Comparison of mercury concentrations measured at several sites in the Southern Hemisphere |
| VerfasserIn |
F. Slemr, H. Angot, A. Dommergue, O. Magand, M. Barret, A. Weigelt, R. Ebinghaus, E.-G. Brunke, K. A. Pfaffhuber, G. Edwards, D. Howard, J. Powell, M. Keywood, F. Wang |
| 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 ; 15, no. 6 ; Nr. 15, no. 6 (2015-03-19), S.3125-3133 |
| Datensatznummer |
250119563
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| Publikation (Nr.) |
 copernicus.org/acp-15-3125-2015.pdf |
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| Zusammenfassung |
| Our knowledge of the distribution of mercury concentrations in air of the
Southern Hemisphere was until recently based mostly on intermittent
measurements made during ship cruises. In the last few years continuous
mercury monitoring has commenced at several sites in the Southern Hemisphere,
providing new and more refined information. In this paper we compare mercury
measurements at several remote sites in the Southern Hemisphere made over a
period of at least 1 year at each location. Averages of monthly medians show
similar although small seasonal variations at both Cape Point and Amsterdam
Island. A pronounced seasonal variation at Troll research station in
Antarctica is due to frequent mercury depletion events in the austral spring.
Due to large scatter and large standard deviations of monthly average median
mercury concentrations at Cape Grim, no systematic seasonal variation could
be found there. Nevertheless, the annual average mercury concentrations at
all sites during the 2007–2013 period varied only between 0.85 and
1.05 ng m−3. Part of this variability is likely due to systematic
measurement uncertainties which we propose can be further reduced by improved
calibration procedures. We conclude that mercury is much more uniformly
distributed throughout the Southern Hemisphere than the distributions
suggested by measurements made onboard ships. This finding implies that
smaller trends can be detected in shorter time periods. We also report a
change in the trend sign at Cape Point from decreasing mercury concentrations
in 1996–2004 to increasing concentrations since 2007. |
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