How to Recognize a True Mode of Atmospheric Circulation Variability
Abstract It has been demonstrated several times that when principal component analysis (PCA) is used for detection of modes of atmospheric circulation variability (teleconnections), principal components must be rotated. Despite it, unrotated PCA is still often used. Here we demonstrate on the exampl...
Published in: | Earth and Space Science |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Geophysical Union (AGU)
2021
|
Subjects: | |
Online Access: | https://doi.org/10.1029/2020EA001275 https://doaj.org/article/df56cb7e447d4e2384724290d3c674a6 |
id |
ftdoajarticles:oai:doaj.org/article:df56cb7e447d4e2384724290d3c674a6 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:df56cb7e447d4e2384724290d3c674a6 2023-05-15T14:59:15+02:00 How to Recognize a True Mode of Atmospheric Circulation Variability Radan Huth Romana Beranová 2021-03-01T00:00:00Z https://doi.org/10.1029/2020EA001275 https://doaj.org/article/df56cb7e447d4e2384724290d3c674a6 EN eng American Geophysical Union (AGU) https://doi.org/10.1029/2020EA001275 https://doaj.org/toc/2333-5084 2333-5084 doi:10.1029/2020EA001275 https://doaj.org/article/df56cb7e447d4e2384724290d3c674a6 Earth and Space Science, Vol 8, Iss 3, Pp n/a-n/a (2021) Arctic oscillation Barents oscillation modes of low‐frequency variability North Atlantic Oscillation principal component analysis teleconnections Astronomy QB1-991 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.1029/2020EA001275 2022-12-31T06:28:48Z Abstract It has been demonstrated several times that when principal component analysis (PCA) is used for detection of modes of atmospheric circulation variability (teleconnections), principal components must be rotated. Despite it, unrotated PCA is still often used. Here we demonstrate on the examples of North Atlantic Oscillation (NAO), Arctic Oscillation (AO), Barents Oscillation (BO), and the summer East Atlantic (SEA) pattern that unrotated PCA results in patterns that are artifacts of the analysis method rather than true modes of variability. This claim is based on the comparison of the spatial patterns of the modes with spatial autocorrelations, on the sensitivity of the patterns to spatial and temporal subsampling, and, for the SEA pattern, on correlations with tropical sea surface temperature. Unlike NAO, which is defined by rotated PCA, the other modes, that is, AO, BO, and SEA pattern, defined by unrotated PCA, do not correspond well to underlying autocorrelation structures and are more sensitive to choices of spatial domain and time interval over which they are defined. We reiterate that a great care must be taken when interpreting outputs of PCA when applied to the detection of modes of circulation variability: a comparison with spatial autocorrelations and check for their spatial and temporal stability are necessary to distinguish true modes from statistical artifacts, which we call “ghost patterns.” Article in Journal/Newspaper Arctic North Atlantic North Atlantic oscillation Directory of Open Access Journals: DOAJ Articles Arctic Earth and Space Science 8 3 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Arctic oscillation Barents oscillation modes of low‐frequency variability North Atlantic Oscillation principal component analysis teleconnections Astronomy QB1-991 Geology QE1-996.5 |
spellingShingle |
Arctic oscillation Barents oscillation modes of low‐frequency variability North Atlantic Oscillation principal component analysis teleconnections Astronomy QB1-991 Geology QE1-996.5 Radan Huth Romana Beranová How to Recognize a True Mode of Atmospheric Circulation Variability |
topic_facet |
Arctic oscillation Barents oscillation modes of low‐frequency variability North Atlantic Oscillation principal component analysis teleconnections Astronomy QB1-991 Geology QE1-996.5 |
description |
Abstract It has been demonstrated several times that when principal component analysis (PCA) is used for detection of modes of atmospheric circulation variability (teleconnections), principal components must be rotated. Despite it, unrotated PCA is still often used. Here we demonstrate on the examples of North Atlantic Oscillation (NAO), Arctic Oscillation (AO), Barents Oscillation (BO), and the summer East Atlantic (SEA) pattern that unrotated PCA results in patterns that are artifacts of the analysis method rather than true modes of variability. This claim is based on the comparison of the spatial patterns of the modes with spatial autocorrelations, on the sensitivity of the patterns to spatial and temporal subsampling, and, for the SEA pattern, on correlations with tropical sea surface temperature. Unlike NAO, which is defined by rotated PCA, the other modes, that is, AO, BO, and SEA pattern, defined by unrotated PCA, do not correspond well to underlying autocorrelation structures and are more sensitive to choices of spatial domain and time interval over which they are defined. We reiterate that a great care must be taken when interpreting outputs of PCA when applied to the detection of modes of circulation variability: a comparison with spatial autocorrelations and check for their spatial and temporal stability are necessary to distinguish true modes from statistical artifacts, which we call “ghost patterns.” |
format |
Article in Journal/Newspaper |
author |
Radan Huth Romana Beranová |
author_facet |
Radan Huth Romana Beranová |
author_sort |
Radan Huth |
title |
How to Recognize a True Mode of Atmospheric Circulation Variability |
title_short |
How to Recognize a True Mode of Atmospheric Circulation Variability |
title_full |
How to Recognize a True Mode of Atmospheric Circulation Variability |
title_fullStr |
How to Recognize a True Mode of Atmospheric Circulation Variability |
title_full_unstemmed |
How to Recognize a True Mode of Atmospheric Circulation Variability |
title_sort |
how to recognize a true mode of atmospheric circulation variability |
publisher |
American Geophysical Union (AGU) |
publishDate |
2021 |
url |
https://doi.org/10.1029/2020EA001275 https://doaj.org/article/df56cb7e447d4e2384724290d3c674a6 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic North Atlantic North Atlantic oscillation |
genre_facet |
Arctic North Atlantic North Atlantic oscillation |
op_source |
Earth and Space Science, Vol 8, Iss 3, Pp n/a-n/a (2021) |
op_relation |
https://doi.org/10.1029/2020EA001275 https://doaj.org/toc/2333-5084 2333-5084 doi:10.1029/2020EA001275 https://doaj.org/article/df56cb7e447d4e2384724290d3c674a6 |
op_doi |
https://doi.org/10.1029/2020EA001275 |
container_title |
Earth and Space Science |
container_volume |
8 |
container_issue |
3 |
_version_ |
1766331367988133888 |