Changes in stratospheric transport and mixing during sudden stratospheric warmings
The extreme disruptions of the wintertime stratospheric circulation during sudden stratospheric warmings (SSW) have large effects on tracer concentrations through alterations in transport. This study analyzes the changes in residual circulation and isentropic mixing associated with SSWs, by performi...
Published in: | Journal of Geophysical Research: Atmospheres |
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Language: | English |
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Online Access: | https://doi.org/10.1002/2017JD028007 |
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ftncar:oai:drupal-site.org:articles_21633 2023-09-05T13:22:43+02:00 Changes in stratospheric transport and mixing during sudden stratospheric warmings de la Cámara, Alvaro (author) Abalos, M. (author) Hitchcock, Adam Peter (author) 2018-04-16 https://doi.org/10.1002/2017JD028007 en eng Journal of Geophysical Research: Atmospheres--J. Geophys. Res. Atmos.--2169897X articles:21633 ark:/85065/d7tt4tp8 doi:10.1002/2017JD028007 Copyright 2018 American Geophysical Union. article Text 2018 ftncar https://doi.org/10.1002/2017JD028007 2023-08-14T18:47:12Z The extreme disruptions of the wintertime stratospheric circulation during sudden stratospheric warmings (SSW) have large effects on tracer concentrations through alterations in transport. This study analyzes the changes in residual circulation and isentropic mixing associated with SSWs, by performing composites using reanalysis (European Centre for Medium-Range Weather Forecasts Re-Analysis Interim) and simulations of the Whole Atmosphere Community Climate Model. The advective Brewer-Dobson circulation accelerates around 15days prior to the wind reversal at 60 degrees N, 10hPa during the onset of SSWs. Soon afterward, it decelerates, leading to reduced advective transport into the vortex and descent over the pole, which persist for more than 2months below 30hPa. The isentropic mixing has a distinct signature in altitude: It is enhanced at the central date of the SSW in the midstratosphere (about 10hPa or 800K), and this signal is delayed and more persistent at lower altitudes. It is shown that sufficiently deep SSWs (particularly those related to Polar-night Jet Oscillation events) have a stronger response in the Brewer-Dobson circulation and mixing. In particular, both the polar downwelling and the tropical upwelling are anomalously weak in the lower stratosphere for 90days after the onset of Polar-night Jet Oscillation events. The redistribution of potential vorticity during the life cycle of SSWs is discussed due to its relevance for the stratospheric circulation. It is shown that the diffusive flux of potential vorticity, calculated in equivalent latitude coordinates, remains anomalously high in the lower stratosphere, a feature that is not seen in more conventional advective eddy fluxes across latitude circles. Article in Journal/Newspaper polar night OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Journal of Geophysical Research: Atmospheres 123 7 3356 3373 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
The extreme disruptions of the wintertime stratospheric circulation during sudden stratospheric warmings (SSW) have large effects on tracer concentrations through alterations in transport. This study analyzes the changes in residual circulation and isentropic mixing associated with SSWs, by performing composites using reanalysis (European Centre for Medium-Range Weather Forecasts Re-Analysis Interim) and simulations of the Whole Atmosphere Community Climate Model. The advective Brewer-Dobson circulation accelerates around 15days prior to the wind reversal at 60 degrees N, 10hPa during the onset of SSWs. Soon afterward, it decelerates, leading to reduced advective transport into the vortex and descent over the pole, which persist for more than 2months below 30hPa. The isentropic mixing has a distinct signature in altitude: It is enhanced at the central date of the SSW in the midstratosphere (about 10hPa or 800K), and this signal is delayed and more persistent at lower altitudes. It is shown that sufficiently deep SSWs (particularly those related to Polar-night Jet Oscillation events) have a stronger response in the Brewer-Dobson circulation and mixing. In particular, both the polar downwelling and the tropical upwelling are anomalously weak in the lower stratosphere for 90days after the onset of Polar-night Jet Oscillation events. The redistribution of potential vorticity during the life cycle of SSWs is discussed due to its relevance for the stratospheric circulation. It is shown that the diffusive flux of potential vorticity, calculated in equivalent latitude coordinates, remains anomalously high in the lower stratosphere, a feature that is not seen in more conventional advective eddy fluxes across latitude circles. |
author2 |
de la Cámara, Alvaro (author) Abalos, M. (author) Hitchcock, Adam Peter (author) |
format |
Article in Journal/Newspaper |
title |
Changes in stratospheric transport and mixing during sudden stratospheric warmings |
spellingShingle |
Changes in stratospheric transport and mixing during sudden stratospheric warmings |
title_short |
Changes in stratospheric transport and mixing during sudden stratospheric warmings |
title_full |
Changes in stratospheric transport and mixing during sudden stratospheric warmings |
title_fullStr |
Changes in stratospheric transport and mixing during sudden stratospheric warmings |
title_full_unstemmed |
Changes in stratospheric transport and mixing during sudden stratospheric warmings |
title_sort |
changes in stratospheric transport and mixing during sudden stratospheric warmings |
publishDate |
2018 |
url |
https://doi.org/10.1002/2017JD028007 |
genre |
polar night |
genre_facet |
polar night |
op_relation |
Journal of Geophysical Research: Atmospheres--J. Geophys. Res. Atmos.--2169897X articles:21633 ark:/85065/d7tt4tp8 doi:10.1002/2017JD028007 |
op_rights |
Copyright 2018 American Geophysical Union. |
op_doi |
https://doi.org/10.1002/2017JD028007 |
container_title |
Journal of Geophysical Research: Atmospheres |
container_volume |
123 |
container_issue |
7 |
container_start_page |
3356 |
op_container_end_page |
3373 |
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1776203238870089728 |