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| Titel |
The Recognition of Multi-Decadal Scale Climate Variability in the Paleo-record over the Past 1000 Years |
| VerfasserIn |
Peter Swart, Amanda Waite, Brad Rosenheim, Chris Moses |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250043645
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| Zusammenfassung |
| Proxy reconstructions of climate from tree rings, corals, stalagmites, sclerosponges, and
deep-sea sediments show multi-decadal climate variability preserved in records extending
back at least 1000 years. Most of these records appear to show a strong correlation with
indices such as the North Atlantic Oscillation (NAO) and the Atlantic Multi-decadal
Oscillation (AMO) over the period of the instrumental record (~1850-present). The repeated
recognition of these signals in a number of different archives and geographical locations
throughout the Atlantic (Cape Verde Islands, Gulf of Guinea, Puerto Rico, Cariaco Basin ,
South Florida, and the Bahamas) strongly suggests that these signals are real and have
climatic significance. The AMO and NAO climate signals are manifested in these indices
through (i) the direct effect of water temperature and salinity on the growth rate of trees and
corals and (ii) temperature and salinity influences on the incorporation of geochemical
proxies, such as the Mg/Ca, Sr/Ca, and oxygen isotopic ratios, into the skeletons of different
carbonate producing organisms. In many areas these relationships are complex and there is
often considerable local variability in the response of corals and trees, particularly in the
growth rate related parameters. Prior to the instrumental period, the tree-ring index compiled
by (Gray et al., 2004, GRL,31) has been taken as the principal reconstruction of the
AMO. While most of the marine records examined appear to correlate with the
tree-ring record during the instrumental period, there are significant discrepancies
prior to 1850. This raises many questions about the stationarity and persistence
of the AMO and the suitability of individual archives such as tree rings for these
modes. |
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