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| Titel |
Halogen species record Antarctic sea ice extent over glacial–interglacial periods |
| VerfasserIn |
A. Spolaor, P. Vallelonga, J. M. C. Plane, N. Kehrwald, J. Gabrieli, C. Varin, C. Turetta, G. Cozzi, R. Kumar, C. Boutron, C. Barbante |
| 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 ; 13, no. 13 ; Nr. 13, no. 13 (2013-07-12), S.6623-6635 |
| Datensatznummer |
250018757
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| Publikation (Nr.) |
 copernicus.org/acp-13-6623-2013.pdf |
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| Zusammenfassung |
| Sea ice is an integral part of the earth's climate system because it affects
planetary albedo, sea-surface salinity, and the atmosphere–ocean exchange of
reactive gases and aerosols. Bromine and iodine chemistry is active at polar
sea ice margins with the occurrence of bromine explosions and the biological
production of organoiodine from sea ice algae. Satellite measurements
demonstrate that concentrations of bromine oxide (BrO) and iodine oxide (IO)
decrease over sea ice toward the Antarctic interior. Here we present
speciation measurements of bromine and iodine in the TALDICE (TALos Dome Ice
CorE) ice core (159°11' E, 72°49' S; 2315 m a.s.l.) spanning
the last 215 ky. The Talos Dome ice core is located 250 km inland and is
sensitive to marine air masses intruding onto the Antarctic Plateau. Talos
Dome bromide (Br−) is positively correlated with temperature and
negatively correlated with sodium (Na). Based on the Br−/Na seawater
ratio, bromide is depleted in the ice during glacial periods and enriched
during interglacial periods. Total iodine, consisting of iodide (I−)
and iodate (IO3−), peaks during glacials with lower values during
interglacial periods. Although IO3− is considered the most stable
iodine species in the atmosphere it was only observed in the TALDICE record
during glacial maxima. Sea ice dynamics are arguably the primary driver of
halogen fluxes over glacial–interglacial timescales, by altering the
distance between the sea ice edge and the Antarctic plateau and by altering
the surface area of sea ice available to algal colonization. Based on our
results we propose the use of both halogens for examining Antarctic
variability of past sea ice extent. |
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