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Titel |
A GCM comparison of Pleistocene super-interglacial periods in relation to Lake El'gygytgyn, NE Arctic Russia |
VerfasserIn |
A. J. Coletti, R. M. DeConto, J. Brigham-Grette, M. Melles |
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. 7 ; Nr. 11, no. 7 (2015-07-10), S.979-989 |
Datensatznummer |
250117361
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Publikation (Nr.) |
copernicus.org/cp-11-979-2015.pdf |
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Zusammenfassung |
Until now, the lack of time-continuous, terrestrial paleoenvironmental
data from the Pleistocene Arctic has made model simulations of past
interglacials difficult to assess. Here, we compare climate simulations of
four warm interglacials at Marine Isotope Stages (MISs) 1 (9 ka), 5e (127 ka),
11c (409 ka) and 31 (1072 ka) with new proxy climate data recovered from
Lake El'gygytgyn, NE Russia. Climate reconstructions of the mean temperature
of the warmest month (MTWM) indicate conditions up to 0.4, 2.1, 0.5 and 3.1 °C warmer than today during MIS 1, 5e, 11c and 31,
respectively. While the climate model captures much of the observed warming
during each interglacial, largely in response to boreal summer (JJA) orbital
forcing, the extraordinary warmth of MIS 11c compared to the other
interglacials in the Lake El'gygytgyn temperature proxy reconstructions
remains difficult to explain. To deconvolve the contribution of multiple
influences on interglacial warming at Lake El'gygytgyn, we isolated the
influence of vegetation, sea ice and circum-Arctic land ice feedbacks on
the modeled climate of the Beringian interior. Simulations accounting for
climate–vegetation–land-surface feedbacks during all four interglacials show
expanding boreal forest cover with increasing summer insolation intensity. A
deglaciated Greenland is shown to have a minimal effect on northeast Asian
temperature during the warmth of stages 11c and 31 (Melles et al., 2012). A prescribed
enhancement of oceanic heat transport into the Arctic Ocean does have some
effect on Lake El'gygytgyn's regional climate, but the exceptional warmth of
MIS l1c remains enigmatic compared to the modest orbital and greenhouse gas
forcing during that interglacial. |
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