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| Titel |
Interpolation methods for Antarctic ice-core timescales: application to Byrd, Siple Dome and Law Dome ice cores |
| VerfasserIn |
T. J. Fudge, E. D. Waddington, H. Conway, J. M. D. Lundin, K. Taylor |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 10, no. 3 ; Nr. 10, no. 3 (2014-06-19), S.1195-1209 |
| Datensatznummer |
250116986
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| Publikation (Nr.) |
 copernicus.org/cp-10-1195-2014.pdf |
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| Zusammenfassung |
| Antarctic ice cores have often been dated by matching distinctive features of
atmospheric methane to those detected in annually dated ice cores from
Greenland. Establishing the timescale between these tie-point ages requires
interpolation. While the uncertainty at tie points is relatively well
described, uncertainty of the interpolation is not. Here we assess the
accuracy of three interpolation schemes using data from the WAIS Divide ice
core in West Antarctica; we compare the interpolation methods with the
annually resolved timescale for the past 30 kyr. Linear interpolation yields
large age errors (up to 380 years) between tie points, abrupt changes in
duration of climate events at tie points, and an age bias. Interpolations
based on the smoothest accumulation rate (ACCUM) or the smoothest
annual-layer thickness (ALT) yield timescales that more closely agree with
the annually resolved timescale and do not have abrupt changes in duration at
tie points. We use ALT to assess the uncertainty in existing timescales for
the past 30 kyr from Byrd, Siple Dome, and Law Dome. These ice-core
timescales were developed with methods similar to linear interpolation.
Maximum age differences exceed 1000 years for Byrd and Siple Dome, and
500 years for Law Dome. For the glacial–interglacial transition (21 to
12 kyr), the existing timescales are, on average, older than ALT by
40 years for Byrd, 240 years for Siple Dome, and 150 years for Law Dome.
Because interpolation uncertainty is often not considered, age uncertainties
for ice-core records are often underestimated. |
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