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| Titel |
Analysing the degree of replication of palaeoclimate records |
| VerfasserIn |
Norbert Marwan, Patrick Koethur, Carl Witt, Sebastian F. M. Breitenbach, Mike Sips |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250105436
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| Publikation (Nr.) |
 EGU/EGU2015-4960.pdf |
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| Zusammenfassung |
| Palaeoclimate proxy records (such as time series derived from ice cores or stalagmites) from
the same or nearby location would be expected to represent similar climate variation. This is
called replication of proxy records but is often difficult to achieve, because either the proxies
are not reflecting the paleoclimate variation, external factors overprint the climate signal in
the proxy record, or chronological uncertainties cause a serious mismatch between the
individual records. In order to minimize the later issue and take the chronological
uncertainties into account, we combine a Monte Carlo based approach (COPRA) with an
ensemble based windowed cross-correlation analysis. This allows the investigation of
potential replication of proxy records from a statistical perspective. We demonstrate
this approach by comparing two stalagmite δ18O records from Heshang cave and
Sanbao cave, both strongly influenced by the East Asian Summer Monsoon and
covering the period between 9000ÂyrÂBP and 500ÂyrBP. We find that both proxy
records reproduce well, although not perfectly. Main issues are differences between
the records caused by unresolved geochemical processes influencing the U-series
system and possibly kinetic fractionation in the oxygen isotope system. Overall, the
proposed approach can provide a means to extract a correction function which
reduces the uncertainties in the dating procedure. This method is a precursory step
towards composite reconstructions that are based on multiple, replicating, time series. |
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