The North Atlantic variability structure, storm tracks, and precipitation depending on the polar vortex strength
International audience Motivated by the strong evidence that the state of the northern hemisphere vortex in boreal winter influences tropospheric variability, teleconnection patterns over the North Atlantic are defined separately for winter episodes where the zonal wind at 50hPa and 65° N is above o...
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ftccsdartic:oai:HAL:hal-00295595v1 2023-11-12T04:13:36+01:00 The North Atlantic variability structure, storm tracks, and precipitation depending on the polar vortex strength Walter, K. Graf, H.-F. Max Planck Institute for Meteorology (MPI-M) Max-Planck-Gesellschaft Centre for Atmospheric Science Cambridge, UK University of Cambridge UK (CAM) 2005-02-01 https://hal.science/hal-00295595 https://hal.science/hal-00295595/document https://hal.science/hal-00295595/file/acp-5-239-2005.pdf en eng HAL CCSD European Geosciences Union hal-00295595 https://hal.science/hal-00295595 https://hal.science/hal-00295595/document https://hal.science/hal-00295595/file/acp-5-239-2005.pdf info:eu-repo/semantics/OpenAccess ISSN: 1680-7316 EISSN: 1680-7324 Atmospheric Chemistry and Physics https://hal.science/hal-00295595 Atmospheric Chemistry and Physics, 2005, 5 (1), pp.239-248 [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere info:eu-repo/semantics/article Journal articles 2005 ftccsdartic 2023-10-21T23:17:42Z International audience Motivated by the strong evidence that the state of the northern hemisphere vortex in boreal winter influences tropospheric variability, teleconnection patterns over the North Atlantic are defined separately for winter episodes where the zonal wind at 50hPa and 65° N is above or below the critical velocity for vertical propagation of zonal planetary wave 1. We argue that the teleconnection structure in the middle and upper troposphere differs considerably between the two regimes of the polar vortex, while this is not the case at sea level. If the polar vortex is strong, there exists one meridional dipole structure of geopotential height in the upper and middle troposphere, which is situated in the central North Atlantic. If the polar vortex is weak, there exist two such dipoles, one over the western and one over the eastern North Atlantic. Storm tracks (and precipitation related with these) are determined by mid and upper tropospheric conditions and we find significant differences of these parameters between the stratospheric regimes. For the strong polar vortex regime, in case of a negative upper tropospheric "NAO" index we find a blocking height situation over the Northeast Atlantic and the strongest storm track of all. It is reaching far north into the Arctic Ocean and has a secondary maximum over the Denmark Strait. Such storm track is not found in composites based on a classic NAO defined by surface pressure differences between the Icelandic Low and the Azores High. Our results suggest that it is important to include the state of the polar vortex strength in any study of the variability over the North Atlantic. Article in Journal/Newspaper Arctic Arctic Ocean Denmark Strait North Atlantic Northeast Atlantic Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Arctic Arctic Ocean |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere Walter, K. Graf, H.-F. The North Atlantic variability structure, storm tracks, and precipitation depending on the polar vortex strength |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
description |
International audience Motivated by the strong evidence that the state of the northern hemisphere vortex in boreal winter influences tropospheric variability, teleconnection patterns over the North Atlantic are defined separately for winter episodes where the zonal wind at 50hPa and 65° N is above or below the critical velocity for vertical propagation of zonal planetary wave 1. We argue that the teleconnection structure in the middle and upper troposphere differs considerably between the two regimes of the polar vortex, while this is not the case at sea level. If the polar vortex is strong, there exists one meridional dipole structure of geopotential height in the upper and middle troposphere, which is situated in the central North Atlantic. If the polar vortex is weak, there exist two such dipoles, one over the western and one over the eastern North Atlantic. Storm tracks (and precipitation related with these) are determined by mid and upper tropospheric conditions and we find significant differences of these parameters between the stratospheric regimes. For the strong polar vortex regime, in case of a negative upper tropospheric "NAO" index we find a blocking height situation over the Northeast Atlantic and the strongest storm track of all. It is reaching far north into the Arctic Ocean and has a secondary maximum over the Denmark Strait. Such storm track is not found in composites based on a classic NAO defined by surface pressure differences between the Icelandic Low and the Azores High. Our results suggest that it is important to include the state of the polar vortex strength in any study of the variability over the North Atlantic. |
author2 |
Max Planck Institute for Meteorology (MPI-M) Max-Planck-Gesellschaft Centre for Atmospheric Science Cambridge, UK University of Cambridge UK (CAM) |
format |
Article in Journal/Newspaper |
author |
Walter, K. Graf, H.-F. |
author_facet |
Walter, K. Graf, H.-F. |
author_sort |
Walter, K. |
title |
The North Atlantic variability structure, storm tracks, and precipitation depending on the polar vortex strength |
title_short |
The North Atlantic variability structure, storm tracks, and precipitation depending on the polar vortex strength |
title_full |
The North Atlantic variability structure, storm tracks, and precipitation depending on the polar vortex strength |
title_fullStr |
The North Atlantic variability structure, storm tracks, and precipitation depending on the polar vortex strength |
title_full_unstemmed |
The North Atlantic variability structure, storm tracks, and precipitation depending on the polar vortex strength |
title_sort |
north atlantic variability structure, storm tracks, and precipitation depending on the polar vortex strength |
publisher |
HAL CCSD |
publishDate |
2005 |
url |
https://hal.science/hal-00295595 https://hal.science/hal-00295595/document https://hal.science/hal-00295595/file/acp-5-239-2005.pdf |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean Denmark Strait North Atlantic Northeast Atlantic |
genre_facet |
Arctic Arctic Ocean Denmark Strait North Atlantic Northeast Atlantic |
op_source |
ISSN: 1680-7316 EISSN: 1680-7324 Atmospheric Chemistry and Physics https://hal.science/hal-00295595 Atmospheric Chemistry and Physics, 2005, 5 (1), pp.239-248 |
op_relation |
hal-00295595 https://hal.science/hal-00295595 https://hal.science/hal-00295595/document https://hal.science/hal-00295595/file/acp-5-239-2005.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782331534071562240 |