### Abstract

The extended empirical orthogonal function (EEOF) analysis of signals containing a standing wave component is considered. It is shown using a simple analytical model that for a single time-lag EEOF analysis, two EEOF patterns describe the standing wave, and that their associated eigenvalues become degenerate if the lag chosen is close to a zero of the sample autocovariance function of the standing wave time series. This degeneracy strongly affects the relative magnitudes of the two sectors of each EEOF pattern and the structure of the associated spatial pattern. A set of EEOF analysis of varying lags is performed on a tropical Pacific sea level pressure (SLP) dataset, known to be dominated by standing variance, and the predictions of the analytical model are verified. As well, it is seen that at degeneracy there is a reduction in the quality of the spatial patterns produced by the EEOF analysis.

Original language | English |
---|---|

Pages (from-to) | 241-254 |

Number of pages | 14 |

Journal | Atmosphere - Ocean |

Volume | 37 |

Issue number | 3 |

Publication status | Published - Sep 1999 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Atmospheric Science
- Oceanography

### Cite this

*Atmosphere - Ocean*,

*37*(3), 241-254.

**A potential problem with extended EOF analysis of standing wave fields.** / Monahan, Adam H.; Tangang @ Tajudin Mahmud, Fredolin; Hsieh, William W.

Research output: Contribution to journal › Article

*Atmosphere - Ocean*, vol. 37, no. 3, pp. 241-254.

}

TY - JOUR

T1 - A potential problem with extended EOF analysis of standing wave fields

AU - Monahan, Adam H.

AU - Tangang @ Tajudin Mahmud, Fredolin

AU - Hsieh, William W.

PY - 1999/9

Y1 - 1999/9

N2 - The extended empirical orthogonal function (EEOF) analysis of signals containing a standing wave component is considered. It is shown using a simple analytical model that for a single time-lag EEOF analysis, two EEOF patterns describe the standing wave, and that their associated eigenvalues become degenerate if the lag chosen is close to a zero of the sample autocovariance function of the standing wave time series. This degeneracy strongly affects the relative magnitudes of the two sectors of each EEOF pattern and the structure of the associated spatial pattern. A set of EEOF analysis of varying lags is performed on a tropical Pacific sea level pressure (SLP) dataset, known to be dominated by standing variance, and the predictions of the analytical model are verified. As well, it is seen that at degeneracy there is a reduction in the quality of the spatial patterns produced by the EEOF analysis.

AB - The extended empirical orthogonal function (EEOF) analysis of signals containing a standing wave component is considered. It is shown using a simple analytical model that for a single time-lag EEOF analysis, two EEOF patterns describe the standing wave, and that their associated eigenvalues become degenerate if the lag chosen is close to a zero of the sample autocovariance function of the standing wave time series. This degeneracy strongly affects the relative magnitudes of the two sectors of each EEOF pattern and the structure of the associated spatial pattern. A set of EEOF analysis of varying lags is performed on a tropical Pacific sea level pressure (SLP) dataset, known to be dominated by standing variance, and the predictions of the analytical model are verified. As well, it is seen that at degeneracy there is a reduction in the quality of the spatial patterns produced by the EEOF analysis.

UR - http://www.scopus.com/inward/record.url?scp=0033269201&partnerID=8YFLogxK

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M3 - Article

VL - 37

SP - 241

EP - 254

JO - Atmosphere - Ocean

JF - Atmosphere - Ocean

SN - 0705-5900

IS - 3

ER -