Abrupt stratospheric vortex weakening associated with North Atlantic anticyclonic wave breaking
The sudden stratospheric warming (SSW) of 12 February 2018 was not forecast by any extended-range model beyond 12 days. From early February, all forecast models that com prise the subseasonal-to-seasonal (S2S) database abruptly transitioned from indicating a strong stratospheric polar vortex (SPV) t...
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Online Access: | https://centaur.reading.ac.uk/85477/ https://centaur.reading.ac.uk/85477/1/Lee_et_al_2019_accepted.pdf https://doi.org/10.1029/2019JD030940 |
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ftunivreading:oai:centaur.reading.ac.uk:85477 2024-09-15T18:09:58+00:00 Abrupt stratospheric vortex weakening associated with North Atlantic anticyclonic wave breaking Lee, S. H. Charlton-Perez, Andrew Furtado, J. C. Woolnough, Steven 2019-08-16 text https://centaur.reading.ac.uk/85477/ https://centaur.reading.ac.uk/85477/1/Lee_et_al_2019_accepted.pdf https://doi.org/10.1029/2019JD030940 en eng American Geophysical Union https://centaur.reading.ac.uk/85477/1/Lee_et_al_2019_accepted.pdf Lee, S. H., Charlton-Perez, A. <https://centaur.reading.ac.uk/view/creators/90000511.html> orcid:0000-0001-8179-6220 , Furtado, J. C. and Woolnough, S. <https://centaur.reading.ac.uk/view/creators/90000455.html> orcid:0000-0003-0500-8514 (2019) Abrupt stratospheric vortex weakening associated with North Atlantic anticyclonic wave breaking. Journal of Geophysical Research: Atmospheres, 124 (15). pp. 8563-8575. ISSN 2169-897X doi: https://doi.org/10.1029/2019JD030940 <https://doi.org/10.1029/2019JD030940> Article PeerReviewed 2019 ftunivreading https://doi.org/10.1029/2019JD030940 2024-07-30T14:08:25Z The sudden stratospheric warming (SSW) of 12 February 2018 was not forecast by any extended-range model beyond 12 days. From early February, all forecast models that com prise the subseasonal-to-seasonal (S2S) database abruptly transitioned from indicating a strong stratospheric polar vortex (SPV) to a high likelihood of a major SSW. We demonstrate that this forecast evolution was associated with the track and intensity of a cyclone in the north-east Atlantic, with an associated anticyclonic Rossby wave break, which was not well-forecast. The wave break played a pivotal role in building the Ural high, which existing literature has shown was a precursor of the 2018 SSW. The track of the cyclone built an anomalously strong sea-level pressure dipole between Scandinavia and Greenland (termed the S-G dipole) which we use as a diagnostic of the wave break. Forecasts which did not capture the magnitude of this event had the largest errors in the SPV strength and did not show enhanced vertical wave activity. A composite of similarly strong wintertime (November{March) S-G dipoles in reanalysis shows associated anticyclonic wave breaking leading to significantly enhanced vertical wave activity and a weakened SPV in the following days, which occured in 35% of the 15-day periods preceding observed major SSWs. Our results indicate a particular transient trigger for weakening the SPV, complementing existing results on the importance of tropospheric blocking for disruptions to the Northern Hemisphere extratropical stratospheric circulation. Article in Journal/Newspaper Greenland North Atlantic North East Atlantic CentAUR: Central Archive at the University of Reading Journal of Geophysical Research: Atmospheres 124 15 8563 8575 |
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Open Polar |
collection |
CentAUR: Central Archive at the University of Reading |
op_collection_id |
ftunivreading |
language |
English |
description |
The sudden stratospheric warming (SSW) of 12 February 2018 was not forecast by any extended-range model beyond 12 days. From early February, all forecast models that com prise the subseasonal-to-seasonal (S2S) database abruptly transitioned from indicating a strong stratospheric polar vortex (SPV) to a high likelihood of a major SSW. We demonstrate that this forecast evolution was associated with the track and intensity of a cyclone in the north-east Atlantic, with an associated anticyclonic Rossby wave break, which was not well-forecast. The wave break played a pivotal role in building the Ural high, which existing literature has shown was a precursor of the 2018 SSW. The track of the cyclone built an anomalously strong sea-level pressure dipole between Scandinavia and Greenland (termed the S-G dipole) which we use as a diagnostic of the wave break. Forecasts which did not capture the magnitude of this event had the largest errors in the SPV strength and did not show enhanced vertical wave activity. A composite of similarly strong wintertime (November{March) S-G dipoles in reanalysis shows associated anticyclonic wave breaking leading to significantly enhanced vertical wave activity and a weakened SPV in the following days, which occured in 35% of the 15-day periods preceding observed major SSWs. Our results indicate a particular transient trigger for weakening the SPV, complementing existing results on the importance of tropospheric blocking for disruptions to the Northern Hemisphere extratropical stratospheric circulation. |
format |
Article in Journal/Newspaper |
author |
Lee, S. H. Charlton-Perez, Andrew Furtado, J. C. Woolnough, Steven |
spellingShingle |
Lee, S. H. Charlton-Perez, Andrew Furtado, J. C. Woolnough, Steven Abrupt stratospheric vortex weakening associated with North Atlantic anticyclonic wave breaking |
author_facet |
Lee, S. H. Charlton-Perez, Andrew Furtado, J. C. Woolnough, Steven |
author_sort |
Lee, S. H. |
title |
Abrupt stratospheric vortex weakening associated with North Atlantic anticyclonic wave breaking |
title_short |
Abrupt stratospheric vortex weakening associated with North Atlantic anticyclonic wave breaking |
title_full |
Abrupt stratospheric vortex weakening associated with North Atlantic anticyclonic wave breaking |
title_fullStr |
Abrupt stratospheric vortex weakening associated with North Atlantic anticyclonic wave breaking |
title_full_unstemmed |
Abrupt stratospheric vortex weakening associated with North Atlantic anticyclonic wave breaking |
title_sort |
abrupt stratospheric vortex weakening associated with north atlantic anticyclonic wave breaking |
publisher |
American Geophysical Union |
publishDate |
2019 |
url |
https://centaur.reading.ac.uk/85477/ https://centaur.reading.ac.uk/85477/1/Lee_et_al_2019_accepted.pdf https://doi.org/10.1029/2019JD030940 |
genre |
Greenland North Atlantic North East Atlantic |
genre_facet |
Greenland North Atlantic North East Atlantic |
op_relation |
https://centaur.reading.ac.uk/85477/1/Lee_et_al_2019_accepted.pdf Lee, S. H., Charlton-Perez, A. <https://centaur.reading.ac.uk/view/creators/90000511.html> orcid:0000-0001-8179-6220 , Furtado, J. C. and Woolnough, S. <https://centaur.reading.ac.uk/view/creators/90000455.html> orcid:0000-0003-0500-8514 (2019) Abrupt stratospheric vortex weakening associated with North Atlantic anticyclonic wave breaking. Journal of Geophysical Research: Atmospheres, 124 (15). pp. 8563-8575. ISSN 2169-897X doi: https://doi.org/10.1029/2019JD030940 <https://doi.org/10.1029/2019JD030940> |
op_doi |
https://doi.org/10.1029/2019JD030940 |
container_title |
Journal of Geophysical Research: Atmospheres |
container_volume |
124 |
container_issue |
15 |
container_start_page |
8563 |
op_container_end_page |
8575 |
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1810447577999474688 |