Antarctic springtime depletion of atmospheric mercury.
Unlike other heavy metals that are inherently associated with atmospheric aerosols, mercury in ambient air exists predominantly in the gaseous elemental form. Because of its prolonged atmospheric residence time, elemental mercury vapor is distributed on a global scale. Recently, Canadian researchers have discovered that total gaseous mercury levels in the lower tropospheric boundary layer in the Canadian Arctic are often significantly depleted during the months after polar sunrise. A possible explanation may involve oxidation of elemental mercury, followed by adsorption and deposition of the oxidized form, leading to an increased input of atmospheric mercury into the Arctic ecosystem. Here we present the first continuous high-time-resolution measurements of total gaseous mercury in the Antarctic covering a 12-month period between January 2000 and January 2001 at the German Antarctic research station Neumayer (70 degrees 39' S, 8 degrees 15' W). We report that mercury depletion events also occur in the Antarctic after polar sunrise and compare our measurements with a data setfrom Alert, Nunavut, Canada. We also present indications that BrO radicals and ozone play a key role in the boundary-layer chemistry during springtime mercury depletion events in the Antarctic troposphere.
Ebinghaus
Ralf
R
Institute for Coastal Research/Physical and Chemical Analysis, GKSS Research Centre Geesthacht, Germany. ralf.ebinghaus@gkss.de
Kock
Hans H
HH
Temme
Christian
C
Einax
Jürgen W
JW
Lowe
Astrid G
AG
Richter
Andreas
A
Burrows
John P
JP
Schroeder
William H
WH
D000327:Adsorption; D000393:Air Pollutants / Q000032:analysis*; D000864:Antarctic Regions; D004784:Environmental Monitoring; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D010084:Oxidation-Reduction; D010507:Periodicity; D012621:Seasons
D000393:Air Pollutants; D008628:Mercury