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| Titel |
Modelling of mineral dust for interglacial and glacial climate conditions with a focus on Antarctica |
| VerfasserIn |
N. Sudarchikova, U. Mikolajewicz, C. Timmreck, D. O'Donnell, G. Schurgers, D. Sein, K. Zhang |
| 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 ; 11, no. 5 ; Nr. 11, no. 5 (2015-05-19), S.765-779 |
| Datensatznummer |
250117285
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| Publikation (Nr.) |
 copernicus.org/cp-11-765-2015.pdf |
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| Zusammenfassung |
| The mineral dust cycle responds to climate variations and plays an
important role in the climate system by affecting the radiative
balance of the atmosphere and modifying biogeochemistry. Polar ice
cores provide unique information about deposition of aeolian dust
particles transported over long distances. These cores are
a palaeoclimate proxy archive of climate variability thousands of years
ago. The current study is a first attempt to simulate past
interglacial dust cycles with a global aerosol–climate model
ECHAM5-HAM. The results are used to explain the dust deposition
changes in Antarctica in terms of quantitative contribution of
different processes, such as emission, atmospheric transport and
precipitation, which will help to interpret palaeodata from Antarctic
ice cores. The investigated periods include four interglacial
time slices: the pre-industrial control (CTRL), mid-Holocene
(6000 yr BP; hereafter referred to as "6 kyr"), last glacial inception (115 000 yr BP; hereafter "115 kyr")
and Eemian (126 000 yr BP; hereafter "126 kyr"). One glacial time interval,
the Last Glacial Maximum (LGM) (21 000 yr BP; hereafter "21 kyr"), was simulated as
well to be a reference test for the model. Results suggest an increase
in mineral dust deposition globally, and in Antarctica, in the past
interglacial periods relative to the pre-industrial CTRL
simulation. Approximately two-thirds of the increase in the
mid-Holocene and Eemian is attributed to enhanced Southern Hemisphere
dust emissions. Slightly strengthened transport efficiency causes the
remaining one-third of the increase in dust deposition. The moderate
change in dust deposition in Antarctica in the last glacial inception
period is caused by the slightly stronger poleward atmospheric
transport efficiency compared to the pre-industrial. Maximum dust
deposition in Antarctica was simulated for the glacial period. LGM
dust deposition in Antarctica is substantially increased due to 2.6
times higher Southern Hemisphere dust emissions, 2 times stronger
atmospheric transport towards Antarctica, and 30% weaker
precipitation over the Southern Ocean. The model is able to reproduce
the order of magnitude of dust deposition globally and in Antarctica
for the pre-industrial and LGM climates. |
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