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| Titel |
Preliminary composite reconstructions of late Holocene summer sea surface temperatures from the North Atlantic. |
| VerfasserIn |
Laura Cunningham, Rob Wilson, Alan Wanamaker Jr, Paul Butler, Jon Eiríksson, Karen-Luise Knudsen, Alix Cage, Bill Austin, Dorthe Klitgaard Kristensen, Thomas Richter, Marie Alexandrine Sicre, Hui Jiang, James Scourse |
| 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 |
250037989
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| Zusammenfassung |
| We present preliminary composite multi-decadal resolution summer (May-October) sea
surface temperature (SST) reconstructions for the North Atlantic region back to
1255 AD. The composite reconstructions are based on SST records from across
the region, derived from a mixture of marine based proxies (diatoms, alkenones,
oxygen isotopes and Mg/Ca ratios from planktonic and benthic foraminifera and
shell increment widths of Arctica islandica). The records used within this study
include 5 records from north of Iceland, 3 from Norway, one from Scotland, and
one from the Rockall Trough (NW of Ireland). Data from all ten sites is available
back to 1430, with data from 9 sites available back to 1255 AD. Although seven
records extend back the full millennium this does not include any records from
Norway, consequently the composite records presented here do not extend back this
far.
Several different approaches have been tested, such as using all the available data, or only
incorporating screened datasets (i.e. data sets correlated with local data after smoothing). The
composite derived from the screened records had a greater amplitude of temperature change
than the reconstruction which included all ten datasets, possibly because the latter
contained more noise. To assess the relative suitability of each method, the results were
compared to the Kaplan SST data-set, averaged over the study region. Overall, a good
coherence (r = ~0.8) was found between the composite records and the Kaplan data.
Comparisons with a terrestrial, multi-proxy reconstruction of arctic temperatures
(Kaufmann et al. 2009) also showed similar trends but with differences in variance.
Several periods of mismatch are observed between the composite records and the
Kaufmann et al. reconstruction, possibly reflecting differences between either terrestrial
and marine realms and/or the North Atlantic and Arctic regions at these times. |
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