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| Titel |
Multi-decadal-scale records of North Atlantic climate variability during the last and present interglacials and preceding glacial terminations. |
| VerfasserIn |
Patricia Jimenez-Amat, Rainer Zahn |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250080928
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| Zusammenfassung |
| High-resolution records of natural interglacial climate variability can provide knowledge if
the currently ongoing climate change and variability are part of or are already beyond
the natural state. Warmer-than-present climatic conditions, a reduced Greenland
Ice Sheet and higher sea level are some of the features the Last Interglacial (LIG,
MIS5e; 129-115 kyr) climate has in common with numerous model projections
of our future climate (Otto-Bliesner et al., 2006; Koop et al., 2009). Establishing
multi-decadal resolution records of past North Atlantic climate variability hence
contributes to a better understanding of the ocean and climate sensitivity of the
wider North Atlantic region. We present palaeoceanographic time series of surface
ocean climatology from Ocean Drilling Program (ODP) Site 976 in the Alboran
Sea, westernmost Mediterranean that span the LIG and Present Interglacial (PIG,
Holocene, 11-0 kyr). The site receives North Atlantic climate signals through the
atmosphere and with the advection of Atlantic inflow waters which in connection with the
high rate of sediment deposition underscores the exceptional quality of the site
to monitor North Atlantic climate variability at multi-decadal resolution (60-90
yrs).
Sea surface temperature (SST) time series derived from Mg/Ca ratios and stable isotope
records (δ18O, δ13C) of the planktonic foraminifera Globigerina bulloides are presented.
Mg/Ca data display similar SST for the climatic optima PIG and LIG. The records compare
well with speleothem and ice core palaeoclimatic profiles, confirming that Site 976
palaeo-profiles reflect climate of the North Atlantic region. The close link between
SSTMg-Caand the LIG δ18O record from the Antro del Corchia speleothem in northern Italy
highlights the strong connection between marine and terrestrial climatology during
that time indicating a farfield contribution of atmospheric signals. Comparison
with SST and benthic δ13C records at North Atlantic sites instructs on regional
climatological offsets and AMOC stability and variability. Correlation with atmospheric
data (ice core palaeo-CO2, δ13Catm) links the North Atlantic climate variability
documented in Site 976 with ocean-to-air gas exchanges that were driven by AMOC
variability.
This is a contribution of the European Commission FP7 Collaborative Project
“Past4Future”. |
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