Model spread in multidecadal North Atlantic Oscillation variability connected to stratosphere–troposphere coupling
The underestimation in multidecadal variability in the wintertime North Atlantic Oscillation (NAO) by global climate models remains poorly understood. Understanding the origins of this weak NAO variability is important for making model projections more reliable. Past studies have linked the weak mul...
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ftdoajarticles:oai:doaj.org/article:4b975201d2ef4ef291b800abd9a52f6d 2024-09-15T18:22:55+00:00 Model spread in multidecadal North Atlantic Oscillation variability connected to stratosphere–troposphere coupling R. Bonnet C. M. McKenna A. C. Maycock 2024-07-01T00:00:00Z https://doi.org/10.5194/wcd-5-913-2024 https://doaj.org/article/4b975201d2ef4ef291b800abd9a52f6d EN eng Copernicus Publications https://wcd.copernicus.org/articles/5/913/2024/wcd-5-913-2024.pdf https://doaj.org/toc/2698-4016 doi:10.5194/wcd-5-913-2024 2698-4016 https://doaj.org/article/4b975201d2ef4ef291b800abd9a52f6d Weather and Climate Dynamics, Vol 5, Pp 913-926 (2024) Meteorology. Climatology QC851-999 article 2024 ftdoajarticles https://doi.org/10.5194/wcd-5-913-2024 2024-08-05T17:48:54Z The underestimation in multidecadal variability in the wintertime North Atlantic Oscillation (NAO) by global climate models remains poorly understood. Understanding the origins of this weak NAO variability is important for making model projections more reliable. Past studies have linked the weak multidecadal NAO variability in models to an underestimated atmospheric response to the Atlantic Multidecadal Variability (AMV). We investigate historical simulations from Coupled Model Intercomparison Project Phase 6 (CMIP6) large-ensemble models and find that most of the models do not reproduce observed multidecadal NAO variability, as found in previous generations of climate models. We explore statistical relationships with physical drivers that may contribute to inter-model spread in NAO variability. There is a significant anticorrelation across models between the AMV–NAO coupling parameter and multidecadal NAO variability over the full historical period ( r = - 0.55 <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="49pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="7ff665c0fd8a821527a47b687bc5e67d"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="wcd-5-913-2024-ie00001.svg" width="49pt" height="10pt" src="wcd-5-913-2024-ie00001.png"/></svg:svg> , p < 0.05 ). However, this relationship is relatively weak and becomes obscured when using a common period (1900–2010) and de-trending the data in a consistent way, with observations to enable a model–data comparison. This suggests that the representation of NAO–AMV coupling contributes to a modest proportion of inter-model spread in multidecadal NAO variability, although the importance of this process for model spread could be underestimated, given evidence of a systematically poor representation of the coupling in the models. We find a significant inter-model correlation between multidecadal NAO variability and multidecadal stratospheric polar vortex variability and a stratosphere–troposphere coupling parameter, ... Article in Journal/Newspaper North Atlantic North Atlantic oscillation Directory of Open Access Journals: DOAJ Articles Weather and Climate Dynamics 5 3 913 926 |
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topic |
Meteorology. Climatology QC851-999 |
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Meteorology. Climatology QC851-999 R. Bonnet C. M. McKenna A. C. Maycock Model spread in multidecadal North Atlantic Oscillation variability connected to stratosphere–troposphere coupling |
topic_facet |
Meteorology. Climatology QC851-999 |
description |
The underestimation in multidecadal variability in the wintertime North Atlantic Oscillation (NAO) by global climate models remains poorly understood. Understanding the origins of this weak NAO variability is important for making model projections more reliable. Past studies have linked the weak multidecadal NAO variability in models to an underestimated atmospheric response to the Atlantic Multidecadal Variability (AMV). We investigate historical simulations from Coupled Model Intercomparison Project Phase 6 (CMIP6) large-ensemble models and find that most of the models do not reproduce observed multidecadal NAO variability, as found in previous generations of climate models. We explore statistical relationships with physical drivers that may contribute to inter-model spread in NAO variability. There is a significant anticorrelation across models between the AMV–NAO coupling parameter and multidecadal NAO variability over the full historical period ( r = - 0.55 <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="49pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="7ff665c0fd8a821527a47b687bc5e67d"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="wcd-5-913-2024-ie00001.svg" width="49pt" height="10pt" src="wcd-5-913-2024-ie00001.png"/></svg:svg> , p < 0.05 ). However, this relationship is relatively weak and becomes obscured when using a common period (1900–2010) and de-trending the data in a consistent way, with observations to enable a model–data comparison. This suggests that the representation of NAO–AMV coupling contributes to a modest proportion of inter-model spread in multidecadal NAO variability, although the importance of this process for model spread could be underestimated, given evidence of a systematically poor representation of the coupling in the models. We find a significant inter-model correlation between multidecadal NAO variability and multidecadal stratospheric polar vortex variability and a stratosphere–troposphere coupling parameter, ... |
format |
Article in Journal/Newspaper |
author |
R. Bonnet C. M. McKenna A. C. Maycock |
author_facet |
R. Bonnet C. M. McKenna A. C. Maycock |
author_sort |
R. Bonnet |
title |
Model spread in multidecadal North Atlantic Oscillation variability connected to stratosphere–troposphere coupling |
title_short |
Model spread in multidecadal North Atlantic Oscillation variability connected to stratosphere–troposphere coupling |
title_full |
Model spread in multidecadal North Atlantic Oscillation variability connected to stratosphere–troposphere coupling |
title_fullStr |
Model spread in multidecadal North Atlantic Oscillation variability connected to stratosphere–troposphere coupling |
title_full_unstemmed |
Model spread in multidecadal North Atlantic Oscillation variability connected to stratosphere–troposphere coupling |
title_sort |
model spread in multidecadal north atlantic oscillation variability connected to stratosphere–troposphere coupling |
publisher |
Copernicus Publications |
publishDate |
2024 |
url |
https://doi.org/10.5194/wcd-5-913-2024 https://doaj.org/article/4b975201d2ef4ef291b800abd9a52f6d |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
Weather and Climate Dynamics, Vol 5, Pp 913-926 (2024) |
op_relation |
https://wcd.copernicus.org/articles/5/913/2024/wcd-5-913-2024.pdf https://doaj.org/toc/2698-4016 doi:10.5194/wcd-5-913-2024 2698-4016 https://doaj.org/article/4b975201d2ef4ef291b800abd9a52f6d |
op_doi |
https://doi.org/10.5194/wcd-5-913-2024 |
container_title |
Weather and Climate Dynamics |
container_volume |
5 |
container_issue |
3 |
container_start_page |
913 |
op_container_end_page |
926 |
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1810462972161556480 |