Regularised empirical orthogonal functions†
Empirical orthogonal functions, extensively used in weather/climate research, suffer serious geometric drawbacks such as orthogonality in space and time and mixing. The present paper presents a different version, the regularised (or smooth) empirical orthogonal function (EOF) method, by including a...
Published in: | Tellus A: Dynamic Meteorology and Oceanography |
---|---|
Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Stockholm University Press
2016
|
Subjects: | |
Online Access: | https://doi.org/10.3402/tellusa.v68.31723 https://doaj.org/article/cf445bf7175741e6b6a543c899ec3566 |
id |
ftdoajarticles:oai:doaj.org/article:cf445bf7175741e6b6a543c899ec3566 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:cf445bf7175741e6b6a543c899ec3566 2023-05-15T14:52:38+02:00 Regularised empirical orthogonal functions† Abdel Hannachi 2016-10-01T00:00:00Z https://doi.org/10.3402/tellusa.v68.31723 https://doaj.org/article/cf445bf7175741e6b6a543c899ec3566 EN eng Stockholm University Press http://www.tellusa.net/index.php/tellusa/article/view/31723/49053 https://doaj.org/toc/1600-0870 1600-0870 doi:10.3402/tellusa.v68.31723 https://doaj.org/article/cf445bf7175741e6b6a543c899ec3566 Tellus: Series A, Dynamic Meteorology and Oceanography, Vol 68, Iss 0, Pp 1-14 (2016) EOFs Regularised EOFs Generalised eigenvalue problem North Atlantic Oscillation Arctic Oscillation Oceanography GC1-1581 Meteorology. Climatology QC851-999 article 2016 ftdoajarticles https://doi.org/10.3402/tellusa.v68.31723 2022-12-30T21:45:19Z Empirical orthogonal functions, extensively used in weather/climate research, suffer serious geometric drawbacks such as orthogonality in space and time and mixing. The present paper presents a different version, the regularised (or smooth) empirical orthogonal function (EOF) method, by including a regularisation constraint, which originates from the field of regression/correlation of continuous variables. The method includes an extra unknown, the smoothing parameter, and solves a generalised eigenvalue problem and can overcome, therefore, some shortcomings of EOFs. For example, the geometrical constraints satisfied by conventional EOFs are relaxed. In addition, the method can help alleviate the mixing drawback. It can also be used in combination with other methods, which are based on downscaling or dimensionality reduction. The method has been applied to sea level pressure and sea surface temperature and yields an optimal value of the smoothing parameter. The method shows, in particular, that the leading sea level pressure pattern, with substantially larger explained variance compared to its EOF counterpart, has a pronounced Arctic Oscillation compared to the mixed North Atlantic Oscillation/Arctic Oscillation pattern of the leading EOF. The analysis of the remaining leading patterns and the application to sea surface temperature field and trend EOFs are also discussed. Article in Journal/Newspaper Arctic North Atlantic North Atlantic oscillation Directory of Open Access Journals: DOAJ Articles Arctic Tellus A: Dynamic Meteorology and Oceanography 68 1 31723 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
EOFs Regularised EOFs Generalised eigenvalue problem North Atlantic Oscillation Arctic Oscillation Oceanography GC1-1581 Meteorology. Climatology QC851-999 |
spellingShingle |
EOFs Regularised EOFs Generalised eigenvalue problem North Atlantic Oscillation Arctic Oscillation Oceanography GC1-1581 Meteorology. Climatology QC851-999 Abdel Hannachi Regularised empirical orthogonal functions† |
topic_facet |
EOFs Regularised EOFs Generalised eigenvalue problem North Atlantic Oscillation Arctic Oscillation Oceanography GC1-1581 Meteorology. Climatology QC851-999 |
description |
Empirical orthogonal functions, extensively used in weather/climate research, suffer serious geometric drawbacks such as orthogonality in space and time and mixing. The present paper presents a different version, the regularised (or smooth) empirical orthogonal function (EOF) method, by including a regularisation constraint, which originates from the field of regression/correlation of continuous variables. The method includes an extra unknown, the smoothing parameter, and solves a generalised eigenvalue problem and can overcome, therefore, some shortcomings of EOFs. For example, the geometrical constraints satisfied by conventional EOFs are relaxed. In addition, the method can help alleviate the mixing drawback. It can also be used in combination with other methods, which are based on downscaling or dimensionality reduction. The method has been applied to sea level pressure and sea surface temperature and yields an optimal value of the smoothing parameter. The method shows, in particular, that the leading sea level pressure pattern, with substantially larger explained variance compared to its EOF counterpart, has a pronounced Arctic Oscillation compared to the mixed North Atlantic Oscillation/Arctic Oscillation pattern of the leading EOF. The analysis of the remaining leading patterns and the application to sea surface temperature field and trend EOFs are also discussed. |
format |
Article in Journal/Newspaper |
author |
Abdel Hannachi |
author_facet |
Abdel Hannachi |
author_sort |
Abdel Hannachi |
title |
Regularised empirical orthogonal functions† |
title_short |
Regularised empirical orthogonal functions† |
title_full |
Regularised empirical orthogonal functions† |
title_fullStr |
Regularised empirical orthogonal functions† |
title_full_unstemmed |
Regularised empirical orthogonal functions† |
title_sort |
regularised empirical orthogonal functions† |
publisher |
Stockholm University Press |
publishDate |
2016 |
url |
https://doi.org/10.3402/tellusa.v68.31723 https://doaj.org/article/cf445bf7175741e6b6a543c899ec3566 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic North Atlantic North Atlantic oscillation |
genre_facet |
Arctic North Atlantic North Atlantic oscillation |
op_source |
Tellus: Series A, Dynamic Meteorology and Oceanography, Vol 68, Iss 0, Pp 1-14 (2016) |
op_relation |
http://www.tellusa.net/index.php/tellusa/article/view/31723/49053 https://doaj.org/toc/1600-0870 1600-0870 doi:10.3402/tellusa.v68.31723 https://doaj.org/article/cf445bf7175741e6b6a543c899ec3566 |
op_doi |
https://doi.org/10.3402/tellusa.v68.31723 |
container_title |
Tellus A: Dynamic Meteorology and Oceanography |
container_volume |
68 |
container_issue |
1 |
container_start_page |
31723 |
_version_ |
1766323875764764672 |