Stratospheric downward wave reflection events modulate North American weather regimes and cold spells
The Arctic stratospheric polar vortex is an important driver of mid-latitude winter cold spells. One proposed coupling mechanism between the stratospheric polar vortex and the troposphere is upward-propagating planetary waves being reflected downward by the polar vortex. However, while the wave refl...
Published in: | Weather and Climate Dynamics |
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Language: | English |
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Copernicus Publications
2022
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Online Access: | https://doi.org/10.5194/wcd-3-1215-2022 https://noa.gwlb.de/receive/cop_mods_00063326 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00062399/wcd-3-1215-2022.pdf https://wcd.copernicus.org/articles/3/1215/2022/wcd-3-1215-2022.pdf |
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00063326 2023-05-15T15:07:23+02:00 Stratospheric downward wave reflection events modulate North American weather regimes and cold spells Messori, Gabriele Kretschmer, Marlene Lee, Simon H. Wendt, Vivien 2022-11 electronic https://doi.org/10.5194/wcd-3-1215-2022 https://noa.gwlb.de/receive/cop_mods_00063326 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00062399/wcd-3-1215-2022.pdf https://wcd.copernicus.org/articles/3/1215/2022/wcd-3-1215-2022.pdf eng eng Copernicus Publications Weather and Climate Dynamics -- https://www.weather-climate-dynamics.net/ -- 2698-4016 https://doi.org/10.5194/wcd-3-1215-2022 https://noa.gwlb.de/receive/cop_mods_00063326 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00062399/wcd-3-1215-2022.pdf https://wcd.copernicus.org/articles/3/1215/2022/wcd-3-1215-2022.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2022 ftnonlinearchiv https://doi.org/10.5194/wcd-3-1215-2022 2022-11-07T00:12:05Z The Arctic stratospheric polar vortex is an important driver of mid-latitude winter cold spells. One proposed coupling mechanism between the stratospheric polar vortex and the troposphere is upward-propagating planetary waves being reflected downward by the polar vortex. However, while the wave reflection mechanism is well-documented, its role in favouring cold spells is still under-explored. Here, we analyse such stratospheric wave reflections and their impact on the tropospheric circulation and surface temperatures over North America in winter. We present a physically interpretable regional stratospheric wave reflection detection metric and identify the tropospheric circulation anomalies associated with prolonged periods of wave reflection, which we term reflection events. In particular, we characterise the tropospheric anomalies through the lens of North American weather regimes. Stratospheric reflection events show a systematic evolution from a Pacific Trough regime – associated on average with positive temperature anomalies and a near-complete absence of anomalously cold temperatures in North America – to an Alaskan Ridge regime, which favours low temperatures over much of the continent. The most striking feature of the stratospheric reflection events is thus a rapid, continental-scale decrease in temperatures. These emerge as continental-scale cold spells by the end of the reflection events. Stratospheric reflection events are thus highly relevant in a tropospheric predictability perspective. Article in Journal/Newspaper Arctic Niedersächsisches Online-Archiv NOA Arctic Pacific Weather and Climate Dynamics 3 4 1215 1236 |
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Niedersächsisches Online-Archiv NOA |
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ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Messori, Gabriele Kretschmer, Marlene Lee, Simon H. Wendt, Vivien Stratospheric downward wave reflection events modulate North American weather regimes and cold spells |
topic_facet |
article Verlagsveröffentlichung |
description |
The Arctic stratospheric polar vortex is an important driver of mid-latitude winter cold spells. One proposed coupling mechanism between the stratospheric polar vortex and the troposphere is upward-propagating planetary waves being reflected downward by the polar vortex. However, while the wave reflection mechanism is well-documented, its role in favouring cold spells is still under-explored. Here, we analyse such stratospheric wave reflections and their impact on the tropospheric circulation and surface temperatures over North America in winter. We present a physically interpretable regional stratospheric wave reflection detection metric and identify the tropospheric circulation anomalies associated with prolonged periods of wave reflection, which we term reflection events. In particular, we characterise the tropospheric anomalies through the lens of North American weather regimes. Stratospheric reflection events show a systematic evolution from a Pacific Trough regime – associated on average with positive temperature anomalies and a near-complete absence of anomalously cold temperatures in North America – to an Alaskan Ridge regime, which favours low temperatures over much of the continent. The most striking feature of the stratospheric reflection events is thus a rapid, continental-scale decrease in temperatures. These emerge as continental-scale cold spells by the end of the reflection events. Stratospheric reflection events are thus highly relevant in a tropospheric predictability perspective. |
format |
Article in Journal/Newspaper |
author |
Messori, Gabriele Kretschmer, Marlene Lee, Simon H. Wendt, Vivien |
author_facet |
Messori, Gabriele Kretschmer, Marlene Lee, Simon H. Wendt, Vivien |
author_sort |
Messori, Gabriele |
title |
Stratospheric downward wave reflection events modulate North American weather regimes and cold spells |
title_short |
Stratospheric downward wave reflection events modulate North American weather regimes and cold spells |
title_full |
Stratospheric downward wave reflection events modulate North American weather regimes and cold spells |
title_fullStr |
Stratospheric downward wave reflection events modulate North American weather regimes and cold spells |
title_full_unstemmed |
Stratospheric downward wave reflection events modulate North American weather regimes and cold spells |
title_sort |
stratospheric downward wave reflection events modulate north american weather regimes and cold spells |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/wcd-3-1215-2022 https://noa.gwlb.de/receive/cop_mods_00063326 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00062399/wcd-3-1215-2022.pdf https://wcd.copernicus.org/articles/3/1215/2022/wcd-3-1215-2022.pdf |
geographic |
Arctic Pacific |
geographic_facet |
Arctic Pacific |
genre |
Arctic |
genre_facet |
Arctic |
op_relation |
Weather and Climate Dynamics -- https://www.weather-climate-dynamics.net/ -- 2698-4016 https://doi.org/10.5194/wcd-3-1215-2022 https://noa.gwlb.de/receive/cop_mods_00063326 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00062399/wcd-3-1215-2022.pdf https://wcd.copernicus.org/articles/3/1215/2022/wcd-3-1215-2022.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/wcd-3-1215-2022 |
container_title |
Weather and Climate Dynamics |
container_volume |
3 |
container_issue |
4 |
container_start_page |
1215 |
op_container_end_page |
1236 |
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1766338906185269248 |