Spurious Indo‐Pacific Connections to Internal Atlantic Multidecadal Variability Introduced by the Global Temperature Residual Method
The relative contributions of external forcing and internal processes to the observed spatial and temporal characteristics of "Atlantic Multidecadal Variability" (AMV) are still under debate. Here, the efficacy of the commonly-used "global temperature residual method" for isolati...
Published in: | Geophysical Research Letters |
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2023
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Online Access: | https://doi.org/10.1029/2022GL100574 |
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ftncar:oai:drupal-site.org:articles_26196 2023-05-15T17:32:51+02:00 Spurious Indo‐Pacific Connections to Internal Atlantic Multidecadal Variability Introduced by the Global Temperature Residual Method Deser, Clara (author) Phillips, Adam S. (author) 2023-02-16 https://doi.org/10.1029/2022GL100574 unknown Geophysical Research Letters--Geophysical Research Letters--0094-8276--1944-8007 articles:26196 doi:10.1029/2022GL100574 ark:/85065/d7736vv5 article 2023 ftncar https://doi.org/10.1029/2022GL100574 2023-04-10T18:08:58Z The relative contributions of external forcing and internal processes to the observed spatial and temporal characteristics of "Atlantic Multidecadal Variability" (AMV) are still under debate. Here, the efficacy of the commonly-used "global temperature residual method" for isolating the internal component of AMV is investigated by means of model Large Ensembles where the truth is known a priori. In this method, local sea surface temperature variability associated with global-mean temperature (G) is removed via linear regression, and the residuals regressed upon the North Atlantic residual timeseries. We show that this method introduces spurious connections over the Indo-Pacific due to the fact that G in any single realization includes both external and internal components: the latter dominated by influences from Pacific Decadal Variability independent of AMV. This methodological shortcoming can be overcome by using the forced component of G in the residual method applied to individual model realizations and to observations. Article in Journal/Newspaper North Atlantic OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Pacific Geophysical Research Letters 50 3 |
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Open Polar |
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OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
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ftncar |
language |
unknown |
description |
The relative contributions of external forcing and internal processes to the observed spatial and temporal characteristics of "Atlantic Multidecadal Variability" (AMV) are still under debate. Here, the efficacy of the commonly-used "global temperature residual method" for isolating the internal component of AMV is investigated by means of model Large Ensembles where the truth is known a priori. In this method, local sea surface temperature variability associated with global-mean temperature (G) is removed via linear regression, and the residuals regressed upon the North Atlantic residual timeseries. We show that this method introduces spurious connections over the Indo-Pacific due to the fact that G in any single realization includes both external and internal components: the latter dominated by influences from Pacific Decadal Variability independent of AMV. This methodological shortcoming can be overcome by using the forced component of G in the residual method applied to individual model realizations and to observations. |
author2 |
Deser, Clara (author) Phillips, Adam S. (author) |
format |
Article in Journal/Newspaper |
title |
Spurious Indo‐Pacific Connections to Internal Atlantic Multidecadal Variability Introduced by the Global Temperature Residual Method |
spellingShingle |
Spurious Indo‐Pacific Connections to Internal Atlantic Multidecadal Variability Introduced by the Global Temperature Residual Method |
title_short |
Spurious Indo‐Pacific Connections to Internal Atlantic Multidecadal Variability Introduced by the Global Temperature Residual Method |
title_full |
Spurious Indo‐Pacific Connections to Internal Atlantic Multidecadal Variability Introduced by the Global Temperature Residual Method |
title_fullStr |
Spurious Indo‐Pacific Connections to Internal Atlantic Multidecadal Variability Introduced by the Global Temperature Residual Method |
title_full_unstemmed |
Spurious Indo‐Pacific Connections to Internal Atlantic Multidecadal Variability Introduced by the Global Temperature Residual Method |
title_sort |
spurious indo‐pacific connections to internal atlantic multidecadal variability introduced by the global temperature residual method |
publishDate |
2023 |
url |
https://doi.org/10.1029/2022GL100574 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Geophysical Research Letters--Geophysical Research Letters--0094-8276--1944-8007 articles:26196 doi:10.1029/2022GL100574 ark:/85065/d7736vv5 |
op_doi |
https://doi.org/10.1029/2022GL100574 |
container_title |
Geophysical Research Letters |
container_volume |
50 |
container_issue |
3 |
_version_ |
1766131138553708544 |