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| Titel |
Gaseous elemental mercury depletion events observed at Cape Point during 2007–2008 |
| VerfasserIn |
E.-G. Brunke, C. Labuschagne, R. Ebinghaus, H. H. Kock, F. Slemr |
| 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 ; 10, no. 3 ; Nr. 10, no. 3 (2010-02-03), S.1121-1131 |
| Datensatznummer |
250008033
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| Publikation (Nr.) |
 copernicus.org/acp-10-1121-2010.pdf |
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| Zusammenfassung |
| Gaseous mercury in the marine boundary layer has been
measured with a 15 min temporal resolution at the Global Atmosphere Watch
station Cape Point since March 2007. The most prominent features of the data
until July 2008 are the frequent occurrences of pollution (PEs) and
depletion events (DEs). Both types of events originate mostly within a short
transport distance (up to about 100 km), which are embedded in air masses
ranging from marine background to continental. The Hg/CO emission ratios
observed during the PEs are within the range reported for biomass burning
and industrial/urban emissions. The depletion of gaseous mercury during the
DEs is in many cases almost complete and suggests an atmospheric residence
time of elemental mercury as short as a few dozens of hours, which is in
contrast to the commonly used estimate of approximately 1 year. The DEs
observed at Cape Point are not accompanied by simultaneous depletion of
ozone which distinguishes them from the halogen driven atmospheric mercury
depletion events (AMDEs) observed in Polar Regions. Nonetheless, DEs similar
to those observed at Cape Point have also been observed at other places in
the marine boundary layer. Additional measurements of mercury speciation and
of possible mercury oxidants are hence called for to reveal the chemical
mechanism of the newly observed DEs and to assess its importance on larger
scales. |
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