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| Titel |
Evaluation of empirical mode decomposition for quantifying multi-decadal variations in sea level records |
| VerfasserIn |
D. P. Chambers |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
2198-5634
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| Digitales Dokument |
URL |
| Erschienen |
In: Nonlinear Processes in Geophysics Discussions ; 1, no. 2 ; Nr. 1, no. 2 (2014-12-05), S.1833-1854 |
| Datensatznummer |
250115136
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| Publikation (Nr.) |
 copernicus.org/npgd-1-1833-2014.pdf |
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| Zusammenfassung |
| The ability of empirical mode decomposition (EMD) to extract
multidecadal variability from sea level records is tested using three
simulations: one based on a series of purely sinusoidal modes, one
based on scaled climate indices of El Niño and the Pacific Decadal
Oscillation (PDO), and the final one including a single month with an
extreme sea level event. All simulations include random noise of
similar variance to high-frequency variability in the San Francisco
tide gauge record. The intrinsic mode functions (IMFs) computed using
EMD were compared to the prescribed oscillations. In all cases, the
longest-period modes are significantly distorted, with incorrect
amplitudes and phases. This affects the estimated acceleration
computed from the longest periodic IMF. In these simulations, the
acceleration was underestimated in the case with purely sinusoidal
modes, and overestimated by nearly 100% in the case with
prescribed climate modes. Additionally, in all cases, extra
low-frequency modes uncorrelated with the prescribed variability are
found. These experiments suggest that using EMD to identify
multidecadal variability and accelerations in sea level records should
be used with caution. |
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