Mechanisms and predictability of sudden stratospheric warming in winter 2018
In the beginning of February 2018 a rapid deceleration of the westerly circulation in the polar Northern Hemisphere stratosphere took place, and on 12 February the zonal-mean zonal wind at 60∘ N and 10 hPa reversed to easterly in a sudden stratospheric warming (SSW) event. We investigate the role of...
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2020
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00054422 2023-05-15T18:41:27+02:00 Mechanisms and predictability of sudden stratospheric warming in winter 2018 Statnaia, Irina A. Karpechko, Alexey Y. Järvinen, Heikki J. 2020-10 electronic https://doi.org/10.5194/wcd-1-657-2020 https://noa.gwlb.de/receive/cop_mods_00054422 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00054073/wcd-1-657-2020.pdf https://wcd.copernicus.org/articles/1/657/2020/wcd-1-657-2020.pdf eng eng Copernicus Publications Weather and Climate Dynamics -- https://www.weather-climate-dynamics.net/ -- 2698-4016 https://doi.org/10.5194/wcd-1-657-2020 https://noa.gwlb.de/receive/cop_mods_00054422 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00054073/wcd-1-657-2020.pdf https://wcd.copernicus.org/articles/1/657/2020/wcd-1-657-2020.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2020 ftnonlinearchiv https://doi.org/10.5194/wcd-1-657-2020 2022-02-08T22:35:02Z In the beginning of February 2018 a rapid deceleration of the westerly circulation in the polar Northern Hemisphere stratosphere took place, and on 12 February the zonal-mean zonal wind at 60∘ N and 10 hPa reversed to easterly in a sudden stratospheric warming (SSW) event. We investigate the role of the tropospheric forcing in the occurrence of the SSW, its predictability and teleconnection with the Madden–Julian oscillation (MJO) by analysing the European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble forecast. The SSW was preceded by significant synoptic wave activity over the Pacific and Atlantic basins, which led to the upward propagation of wave packets and resulted in the amplification of a stratospheric wavenumber 2 planetary wave. The dynamical and statistical analyses indicate that the main tropospheric forcing resulted from an anticyclonic Rossby wave breaking, subsequent blocking and upward wave propagation in the Ural Mountains region, in agreement with some previous studies. The ensemble members which predicted the wind reversal also reasonably reproduced this chain of events, from the horizontal propagation of individual wave packets to upward wave-activity fluxes and the amplification of wavenumber 2. On the other hand, the ensemble members which failed to predict the wind reversal also failed to properly capture the blocking event in the key region of the Urals and the associated intensification of upward-propagating wave activity. Finally, a composite analysis suggests that teleconnections associated with the record-breaking MJO phase 6 observed in late January 2018 likely played a role in triggering this SSW event. Article in Journal/Newspaper ural mountains ural mountains Niedersächsisches Online-Archiv NOA Pacific Weather and Climate Dynamics 1 2 657 674 |
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Niedersächsisches Online-Archiv NOA |
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English |
topic |
article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Statnaia, Irina A. Karpechko, Alexey Y. Järvinen, Heikki J. Mechanisms and predictability of sudden stratospheric warming in winter 2018 |
topic_facet |
article Verlagsveröffentlichung |
description |
In the beginning of February 2018 a rapid deceleration of the westerly circulation in the polar Northern Hemisphere stratosphere took place, and on 12 February the zonal-mean zonal wind at 60∘ N and 10 hPa reversed to easterly in a sudden stratospheric warming (SSW) event. We investigate the role of the tropospheric forcing in the occurrence of the SSW, its predictability and teleconnection with the Madden–Julian oscillation (MJO) by analysing the European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble forecast. The SSW was preceded by significant synoptic wave activity over the Pacific and Atlantic basins, which led to the upward propagation of wave packets and resulted in the amplification of a stratospheric wavenumber 2 planetary wave. The dynamical and statistical analyses indicate that the main tropospheric forcing resulted from an anticyclonic Rossby wave breaking, subsequent blocking and upward wave propagation in the Ural Mountains region, in agreement with some previous studies. The ensemble members which predicted the wind reversal also reasonably reproduced this chain of events, from the horizontal propagation of individual wave packets to upward wave-activity fluxes and the amplification of wavenumber 2. On the other hand, the ensemble members which failed to predict the wind reversal also failed to properly capture the blocking event in the key region of the Urals and the associated intensification of upward-propagating wave activity. Finally, a composite analysis suggests that teleconnections associated with the record-breaking MJO phase 6 observed in late January 2018 likely played a role in triggering this SSW event. |
format |
Article in Journal/Newspaper |
author |
Statnaia, Irina A. Karpechko, Alexey Y. Järvinen, Heikki J. |
author_facet |
Statnaia, Irina A. Karpechko, Alexey Y. Järvinen, Heikki J. |
author_sort |
Statnaia, Irina A. |
title |
Mechanisms and predictability of sudden stratospheric warming in winter 2018 |
title_short |
Mechanisms and predictability of sudden stratospheric warming in winter 2018 |
title_full |
Mechanisms and predictability of sudden stratospheric warming in winter 2018 |
title_fullStr |
Mechanisms and predictability of sudden stratospheric warming in winter 2018 |
title_full_unstemmed |
Mechanisms and predictability of sudden stratospheric warming in winter 2018 |
title_sort |
mechanisms and predictability of sudden stratospheric warming in winter 2018 |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/wcd-1-657-2020 https://noa.gwlb.de/receive/cop_mods_00054422 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00054073/wcd-1-657-2020.pdf https://wcd.copernicus.org/articles/1/657/2020/wcd-1-657-2020.pdf |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
ural mountains ural mountains |
genre_facet |
ural mountains ural mountains |
op_relation |
Weather and Climate Dynamics -- https://www.weather-climate-dynamics.net/ -- 2698-4016 https://doi.org/10.5194/wcd-1-657-2020 https://noa.gwlb.de/receive/cop_mods_00054422 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00054073/wcd-1-657-2020.pdf https://wcd.copernicus.org/articles/1/657/2020/wcd-1-657-2020.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-1-657-2020 |
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Weather and Climate Dynamics |
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1 |
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2 |
container_start_page |
657 |
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674 |
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