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Titel |
Changes in atmospheric variability in a glacial climate and the impacts on proxy data: a model intercomparison |
VerfasserIn |
F. S. R. Pausata, C. Li, J. J. Wettstein, K. H. Nisancioglu, D. S. Battisti |
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 ; 5, no. 3 ; Nr. 5, no. 3 (2009-09-11), S.489-502 |
Datensatznummer |
250002548
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Publikation (Nr.) |
copernicus.org/cp-5-489-2009.pdf |
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Zusammenfassung |
Using four different climate models, we investigate
sea level pressure variability in the extratropical North Atlantic
in the preindustrial climate (1750 AD) and at the Last Glacial Maximum
(LGM, 21 kyrs before present) in order to understand how changes in
atmospheric circulation can affect signals recorded in climate proxies.
In general, the models exhibit a significant reduction
in interannual variance of sea level pressure at the LGM compared
to pre-industrial simulations and this reduction is concentrated in
winter. For the preindustrial climate, all models feature a similar
leading mode of sea level pressure variability that resembles the
leading mode of variability in the instrumental record: the North
Atlantic Oscillation (NAO). In contrast, the leading mode of sea level
pressure variability at the LGM is model dependent, but in each model
different from that in the preindustrial climate. In each model, the
leading (NAO-like) mode of variability explains a smaller fraction
of the variance and also less absolute variance at the LGM than in
the preindustrial climate.
The models show that the relationship between atmospheric
variability and surface climate (temperature and precipitation) variability
change in different climates. Results are model-specific, but indicate
that proxy signals at the LGM may be misinterpreted if changes in
the spatial pattern and seasonality of surface climate variability
are not taken into account. |
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