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| Titel |
Little Ice Age climate and oceanic conditions of the Ross Sea, Antarctica from a coastal ice core record |
| VerfasserIn |
R. H. Rhodes, N. A. N. Bertler, J. A. Baker, H. C. Steen-Larsen, S. B. Sneed, U. Morgenstern, S. J. Johnsen |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 8, no. 4 ; Nr. 8, no. 4 (2012-07-30), S.1223-1238 |
| Datensatznummer |
250005709
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| Publikation (Nr.) |
 copernicus.org/cp-8-1223-2012.pdf |
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| Zusammenfassung |
| Increasing paleoclimatic evidence suggests that the Little Ice Age (LIA) was
a global climate change event. Understanding the forcings and associated
climate system feedbacks of the LIA is made difficult by the scarcity of
Southern Hemisphere paleoclimate records. We use a new
glaciochemical record of a coastal ice core from Mt. Erebus Saddle,
Antarctica, to reconstruct atmospheric and oceanic conditions in the Ross
Sea sector of Antarctica over the past five centuries. The LIA is identified
in stable isotope (δD) and lithophile element records, which
respectively demonstrate that the region experienced 1.6 ± 1.4 °C
cooler average temperatures prior to 1850 AD than during the
last 150 yr and strong (>57 m s−1) prevailing katabatic
winds between 1500 and 1800 AD. Al and Ti concentration increases of an
order of magnitude (>120 ppb Al) are linked to enhanced aeolian
transport of complex silicate minerals and represent the strongest katabatic
wind events of the LIA. These events are associated with three 12–30 yr
intervals of cooler temperatures at ca. 1690 AD, 1770 AD and 1840 AD.
Furthermore, ice core concentrations of the biogenic sulphur species
MS− suggest that biological productivity in the Ross Sea polynya was
~80% higher prior to 1875 AD than at any subsequent time.
We propose that cooler Antarctic temperatures promoted stronger katabatic
winds across the Ross Ice Shelf, resulting in an enlarged Ross Sea polynya
during the LIA. |
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