 |
| Titel |
Overview of mercury measurements in the Antarctic troposphere |
| VerfasserIn |
A. Dommergue, F. Sprovieri, N. Pirrone, R. Ebinghaus, S. Brooks, J. Courteaud, C. P. Ferrari |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 7 ; Nr. 10, no. 7 (2010-04-07), S.3309-3319 |
| Datensatznummer |
250008331
|
| Publikation (Nr.) |
 copernicus.org/acp-10-3309-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| Polar ecosystems are considered to be the last pristine environments of the
earth relatively uninfluenced by human activities. Antarctica in particular,
compared to the Arctic is considered to be even less affected by any kind of
anthropogenic influences. Once contaminants reach the Polar Regions, their
lifetime in the troposphere depends on local removal processes. Atmospheric
mercury, in particular, has unique characteristics that include long-range
transport to Polar Regions and the transformation to more toxic and
water-soluble compounds that may potentially become bioavailable. These
chemical-physical properties have placed mercury on the priority list of an
increasing number of International, European and National conventions, and
agreements, aimed at the protection of the ecosystems including human health
(i.e. GEO, UNEP, AMAP, UN-ECE, HELCOM, OSPAR). This interest, in turn,
stimulates a significant amount of research including measurements of
gaseous elemental mercury reaction rate constant with atmospheric oxidants,
experimental and modelling studies in order to understand the cycling of
mercury in Polar Regions, and its impact to these ecosystems. Special
attention in terms of contamination of Polar Regions is paid to the
consequences of the springtime phenomena, referred to as "Atmospheric
Mercury Depletion Events" (AMDEs), during which elemental mercury through a
series of photochemically-initiated reactions involving halogens, may be
converted to a reactive form that may accumulate in polar coastal, or sea
ice, ecosystems. The discovery of the AMDEs, first noted in the Arctic, has
also been observed at both poles and was initially considered to result in
an important net input of atmospheric mercury into the polar surfaces.
However, recent studies point out that complex processes take place after
deposition that may result in less significant net-inputs from the
atmosphere since a fraction, sometimes significant, of deposited mercury may
be recycled. Therefore, the contribution of this unique reactivity occurring
in polar atmospheres to the global budget of atmospheric mercury, and the
role played by snow and ice surfaces of these regions, are important issues.
This paper presents a review of atmospheric mercury studies conducted in the
Antarctic troposphere, both at coastal locations and on the Antarctic
Plateau since 1985. Our current understanding of atmospheric reactivity in
this region is also presented. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|