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| Titel |
High-resolution mineral dust and sea ice proxy records from the Talos Dome ice core |
| VerfasserIn |
S. Schüpbach, U. Federer, P. R. Kaufmann, S. Albani, C. Barbante, T. F. Stocker, H. Fischer |
| 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 ; 9, no. 6 ; Nr. 9, no. 6 (2013-12-23), S.2789-2807 |
| Datensatznummer |
250085275
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| Publikation (Nr.) |
 copernicus.org/cp-9-2789-2013.pdf |
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| Zusammenfassung |
In this study we report on new non-sea salt calcium (nssCa2+, mineral
dust proxy) and sea salt sodium (ssNa+, sea ice proxy) records along the
East Antarctic Talos Dome deep ice core in centennial resolution reaching
back 150 thousand years (ka) before present. During glacial conditions
nssCa2+ fluxes in Talos Dome are strongly related to temperature as has
been observed before in other deep Antarctic ice core records, and has been
associated with synchronous changes in the main source region (southern South
America) during climate variations in the last glacial. However, during
warmer climate conditions Talos Dome mineral dust input is clearly elevated
compared to other records mainly due to the contribution of additional local
dust sources in the Ross Sea area. Based on a simple transport model, we
compare nssCa2+ fluxes of different East Antarctic ice cores. From this
multi-site comparison we conclude that changes in transport efficiency or
atmospheric lifetime of dust particles do have a minor effect compared to
source strength changes on the large-scale concentration changes observed in
Antarctic ice cores during climate variations of the past 150 ka. Our
transport model applied on ice core data is further validated by climate
model data.
The availability of multiple East Antarctic nssCa2+ records also allows
for a revision of a former estimate on the atmospheric CO2 sensitivity
to reduced dust induced iron fertilisation in the Southern Ocean during the
transition from the Last Glacial Maximum to the Holocene (T1). While a former
estimate based on the EPICA Dome C (EDC) record only suggested 20 ppm, we
find that reduced dust induced iron fertilisation in the Southern Ocean may
be responsible for up to 40 ppm of the total atmospheric CO2 increase during
T1.
During the last interglacial, ssNa+ levels of EDC and EPICA Dronning
Maud Land (EDML) are only half of the Holocene levels, in line with higher
temperatures during that period, indicating much reduced sea ice extent in
the Atlantic as well as the Indian Ocean sector of the Southern Ocean. In
contrast, Holocene ssNa+ flux in Talos Dome is about the same as during
the last interglacial, indicating that there was similar ice cover present in
the Ross Sea area during MIS 5.5 as during the Holocene. |
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