Synchronizing the Greenland ice core and radiocarbon timescales over the Holocene – Bayesian wiggle-matching of cosmogenic radionuclide records
Investigations of past climate dynamics rely on accurate and precise chronologies of the employed climate reconstructions. The radiocarbon dating calibration curve (IntCal13) and the Greenland ice core chronology (GICC05) represent two of the most widely used chronological frameworks in paleoclimato...
| Главные авторы: | , |
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| Формат: | Статья |
| Язык: | English |
| Опубликовано: |
Copernicus Publications
2016-01-01
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| Серии: | Climate of the Past |
| Online-ссылка: | http://www.clim-past.net/12/15/2016/cp-12-15-2016.pdf |
| Итог: | Investigations of past climate dynamics rely on accurate
and precise chronologies of the employed climate reconstructions. The
radiocarbon dating calibration curve (IntCal13) and the Greenland ice core
chronology (GICC05) represent two of the most widely used chronological
frameworks in paleoclimatology of the past ∼ 50 000 years.
However, comparisons of climate records anchored on these chronologies are
hampered by the precision and accuracy of both timescales. Here we use
common variations in the production rates of <sup>14</sup>C and <sup>10</sup>Be recorded
in tree-rings and ice cores, respectively, to assess the differences between
both timescales during the Holocene. Compared to earlier work, we employ a
novel statistical approach which leads to strongly reduced and yet, more
robust, uncertainty estimates. Furthermore, we demonstrate that the inferred
timescale differences are robust independent of (i) the applied ice core
<sup>10</sup>Be records, (ii) assumptions of the mode of <sup>10</sup>Be deposition, as
well as (iii) carbon cycle effects on <sup>14</sup>C, and (iv) in agreement with
independent estimates of the timescale differences. Our results imply that
the GICC05 counting error is likely underestimated during the most recent
2000 years leading to a dating bias that propagates throughout large parts
of the Holocene. Nevertheless, our analysis indicates that the GICC05
counting error is generally a robust uncertainty measurement but care has to
be taken when treating it as a nearly Gaussian error distribution. The
proposed IntCal13-GICC05 transfer function facilitates the comparison of ice
core and radiocarbon dated paleoclimate records at high chronological
precision. |
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| ISSN: | 1814-9324 1814-9332 |