Comparing and contrasting extreme stratospheric events, including their coupling to the tropospheric circulation
Recent work has emphasized the importance of stratosphere-troposphere coupling associated with extreme values of the polar vortex strength and stratospheric planetary wave heat flux during Northern Hemisphere winter. Here using ERA-Interim reanalysis data the evolution of the two types of events are...
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ftcolumbiauniv:oai:academiccommons.columbia.edu:10.7916/D8M9083C 2023-05-15T17:29:00+02:00 Comparing and contrasting extreme stratospheric events, including their coupling to the tropospheric circulation Dunn-Sigouin, Etienne Shaw, Tiffany Ann 2015 https://doi.org/10.7916/D8M9083C English eng AGU Publications https://doi.org/10.7916/D8M9083C Troposphere Atmospheric thermodynamics Stratosphere Polar vortex Geophysics Atmosphere Articles 2015 ftcolumbiauniv https://doi.org/10.7916/D8M9083C 2019-04-04T08:13:19Z Recent work has emphasized the importance of stratosphere-troposphere coupling associated with extreme values of the polar vortex strength and stratospheric planetary wave heat flux during Northern Hemisphere winter. Here using ERA-Interim reanalysis data the evolution of the two types of events are compared. The life cycle of total (anomaly plus climatology) positive/negative heat flux events are associated with vertically deep high-latitude planetary wave structures and exhibit largely equal but opposite-signed impacts, including a net deceleration/acceleration of the polar vortex due to EP flux convergence/divergence and an equatorward/poleward tropospheric jet shift in the North Atlantic. The tropospheric wave pattern is westward propagating. High-latitude stratospheric vertical zonal wind shear plays a key role during both events. A comparison of the stratospheric events reveals that planetary wave events contribute to the development of vortex events. In particular, total negative heat flux events precede strong vortex events showing that strong vortex events represent true dynamical events involving significant wave-mean flow interaction. Coupling with the North Atlantic jet occurs preceding vortex events when wave-1 dominates the total eddy heat flux in the lower stratosphere since interference with wave-2 makes the impacts less clear. The tropospheric impacts in the North Atlantic associated with planetary wave events are found to be comparable if not larger than those following vortex events. Article in Journal/Newspaper North Atlantic Columbia University: Academic Commons |
institution |
Open Polar |
collection |
Columbia University: Academic Commons |
op_collection_id |
ftcolumbiauniv |
language |
English |
topic |
Troposphere Atmospheric thermodynamics Stratosphere Polar vortex Geophysics Atmosphere |
spellingShingle |
Troposphere Atmospheric thermodynamics Stratosphere Polar vortex Geophysics Atmosphere Dunn-Sigouin, Etienne Shaw, Tiffany Ann Comparing and contrasting extreme stratospheric events, including their coupling to the tropospheric circulation |
topic_facet |
Troposphere Atmospheric thermodynamics Stratosphere Polar vortex Geophysics Atmosphere |
description |
Recent work has emphasized the importance of stratosphere-troposphere coupling associated with extreme values of the polar vortex strength and stratospheric planetary wave heat flux during Northern Hemisphere winter. Here using ERA-Interim reanalysis data the evolution of the two types of events are compared. The life cycle of total (anomaly plus climatology) positive/negative heat flux events are associated with vertically deep high-latitude planetary wave structures and exhibit largely equal but opposite-signed impacts, including a net deceleration/acceleration of the polar vortex due to EP flux convergence/divergence and an equatorward/poleward tropospheric jet shift in the North Atlantic. The tropospheric wave pattern is westward propagating. High-latitude stratospheric vertical zonal wind shear plays a key role during both events. A comparison of the stratospheric events reveals that planetary wave events contribute to the development of vortex events. In particular, total negative heat flux events precede strong vortex events showing that strong vortex events represent true dynamical events involving significant wave-mean flow interaction. Coupling with the North Atlantic jet occurs preceding vortex events when wave-1 dominates the total eddy heat flux in the lower stratosphere since interference with wave-2 makes the impacts less clear. The tropospheric impacts in the North Atlantic associated with planetary wave events are found to be comparable if not larger than those following vortex events. |
format |
Article in Journal/Newspaper |
author |
Dunn-Sigouin, Etienne Shaw, Tiffany Ann |
author_facet |
Dunn-Sigouin, Etienne Shaw, Tiffany Ann |
author_sort |
Dunn-Sigouin, Etienne |
title |
Comparing and contrasting extreme stratospheric events, including their coupling to the tropospheric circulation |
title_short |
Comparing and contrasting extreme stratospheric events, including their coupling to the tropospheric circulation |
title_full |
Comparing and contrasting extreme stratospheric events, including their coupling to the tropospheric circulation |
title_fullStr |
Comparing and contrasting extreme stratospheric events, including their coupling to the tropospheric circulation |
title_full_unstemmed |
Comparing and contrasting extreme stratospheric events, including their coupling to the tropospheric circulation |
title_sort |
comparing and contrasting extreme stratospheric events, including their coupling to the tropospheric circulation |
publisher |
AGU Publications |
publishDate |
2015 |
url |
https://doi.org/10.7916/D8M9083C |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://doi.org/10.7916/D8M9083C |
op_doi |
https://doi.org/10.7916/D8M9083C |
_version_ |
1766122301557833728 |