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| Titel |
Climate spectrum estimation in the presence of timescale errors |
| VerfasserIn |
M. Mudelsee, D. Scholz, R. Röthlisberger, D. Fleitmann, A. Mangini, E. W. Wolff |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1023-5809
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| Digitales Dokument |
URL |
| Erschienen |
In: Nonlinear Processes in Geophysics ; 16, no. 1 ; Nr. 16, no. 1 (2009-02-05), S.43-56 |
| Datensatznummer |
250013086
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| Publikation (Nr.) |
 copernicus.org/npg-16-43-2009.pdf |
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| Zusammenfassung |
| We introduce an
algorithm (called REDFITmc2) for spectrum estimation
in the presence of timescale errors.
It is based on the Lomb-Scargle periodogram
for unevenly spaced time series,
in combination with the
Welch's Overlapped Segment Averaging procedure,
bootstrap bias correction
and
persistence estimation.
The timescale errors are modelled parametrically
and included in the simulations
for determining
(1) the upper levels
of the spectrum of the red-noise AR(1) alternative
and
(2) the uncertainty of the frequency of a spectral peak.
Application of REDFITmc2 to ice core and stalagmite
records of palaeoclimate allowed a more realistic
evaluation of spectral peaks
than when ignoring this source of uncertainty.
The results
support qualitatively the
intuition that stronger effects
on the spectrum estimate
(decreased detectability and increased frequency uncertainty)
occur for higher frequencies.
The surplus information brought by algorithm REDFITmc2
is that those effects are quantified.
Regarding timescale construction,
not only the fixpoints,
dating errors
and the functional form of the age-depth model
play a role.
Also the joint distribution of all time points
(serial correlation, stratigraphic order)
determines spectrum estimation. |
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