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| Titel |
Abrupt climate changes of the last deglaciation detected in a Western Mediterranean forest record |
| VerfasserIn |
W. J. Fletcher, M. F. Sanchez Goñi, O. Peyron, I. Dormoy |
| 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 ; 6, no. 2 ; Nr. 6, no. 2 (2010-04-14), S.245-264 |
| Datensatznummer |
250003447
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| Publikation (Nr.) |
 copernicus.org/cp-6-245-2010.pdf |
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| Zusammenfassung |
| Abrupt changes in Western Mediterranean climate during the last deglaciation
(20 to 6 cal ka BP) are detected in marine core MD95-2043 (Alboran Sea)
through the investigation of high-resolution pollen data and pollen-based
climate reconstructions by the modern analogue technique (MAT) for annual
precipitation (Pann) and mean temperatures of the coldest and warmest
months (MTCO and MTWA). Changes in temperate Mediterranean forest
development and composition and MAT reconstructions indicate major climatic
shifts with parallel temperature and precipitation changes at the onsets of
Heinrich stadial 1 (equivalent to the Oldest Dryas), the
Bölling-Allerød (BA), and the Younger Dryas (YD).
Multi-centennial-scale oscillations in forest development occurred
throughout the BA, YD, and early Holocene. Shifts in vegetation composition
and (Pann reconstructions indicate that forest declines occurred during
dry, and generally cool, episodes centred at 14.0, 13.3, 12.9, 11.8, 10.7,
10.1, 9.2, 8.3 and 7.4 cal ka BP. The forest record also suggests multiple,
low-amplitude Preboreal (PB) climate oscillations, and a marked increase in
moisture availability for forest development at the end of the PB at 10.6 cal ka BP.
Dry atmospheric conditions in the Western Mediterranean occurred
in phase with Lateglacial events of high-latitude cooling including GI-1d
(Older Dryas), GI-1b (Intra-Allerød Cold Period) and GS-1 (YD), and
during Holocene events associated with high-latitude cooling, meltwater
pulses and N. Atlantic ice-rafting. A possible climatic mechanism for the
recurrence of dry intervals and an opposed regional precipitation pattern
with respect to Western-central Europe relates to the dynamics of the
westerlies and the prevalence of atmospheric blocking highs. Comparison of
radiocarbon and ice-core ages for well-defined climatic transitions in the
forest record suggests possible enhancement of marine reservoir ages in the
Alboran Sea by 200 years (surface water age 600 years) during
the Lateglacial. |
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