Observed changes in the southern hemispheric circulation in May
Much research has focused on trends in the Southern Hemispheric circulation in austral summer (December-February) in the troposphere and stratosphere, whereas changes in other seasons have received less attention. Here the seasonality and structure of observed changes in tropospheric and stratospher...
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Online Access: | https://doi.org/10.1175/JCLI-D-16-0394.1 |
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ftncar:oai:drupal-site.org:articles_19460 2023-09-05T13:12:22+02:00 Observed changes in the southern hemispheric circulation in May Ivy, Diane J. (author) Hilgenbrink, Casey (author) Kinnison, Doug (author) Alan Plumb, R. (author) Sheshadri, Aditi (author) Solomon, Susan (author) Thompson, David W. J. (author) 2017-01 https://doi.org/10.1175/JCLI-D-16-0394.1 en eng Journal of Climate--J. Climate--0894-8755--1520-0442 articles:19460 ark:/85065/d7xs5x5r doi:10.1175/JCLI-D-16-0394.1 Copyright 2017 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be "fair use" under Section 107 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Law (17 USC, as revised by P.L. 94-553) does not require the Society's permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statements, requires written permission or license from the AMS. Additional details are provided in the AMS Copyright Policies, available from the AMS at 617-227-2425 or amspubs@ametsoc.org. Permission to place a copy of this work on this server has been provided by the AMS. The AMS does not guarantee that the copy provided here is an accurate copy of the published work. article Text 2017 ftncar https://doi.org/10.1175/JCLI-D-16-0394.1 2023-08-14T18:46:06Z Much research has focused on trends in the Southern Hemispheric circulation in austral summer (December-February) in the troposphere and stratosphere, whereas changes in other seasons have received less attention. Here the seasonality and structure of observed changes in tropospheric and stratospheric winds, temperature, and ozone over the Southern Hemisphere are examined. It is found that statistically significant trends similar to those of the Antarctic summer season are also observed since 1979 in austral fall, particularly May, and are strongest over the Pacific sector of the hemisphere. Evidence is provided for a significant shift in the position of the jet in May over the Pacific, and it is shown that the strengthening and shifting of the jet has rendered the latitudinal distribution of upper-tropospheric zonal wind more bimodal. The Antarctic ozone hole has cooled the lower stratosphere and strengthened the polar vortex. While the mechanism and timing are not fully understood, the ozone hole has been identified as a key driver of the summer season tropospheric circulation changes in several previous observational and modeling studies. It is found here that significant ozone depletion and associated polar cooling also occur in the lower most stratosphere and tropopause region through austral fall, with spatial patterns that are coincident with the observed changes in stratospheric circulation. It is also shown that radiatively driven temperature changes associated with the observed ozone depletion in May represent a substantial portion of the observed May cooling in the lowermost stratosphere, suggesting a potential for contribution to the circulation changes. Article in Journal/Newspaper Antarc* Antarctic OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Antarctic Austral Pacific The Antarctic Journal of Climate 30 2 527 536 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
Much research has focused on trends in the Southern Hemispheric circulation in austral summer (December-February) in the troposphere and stratosphere, whereas changes in other seasons have received less attention. Here the seasonality and structure of observed changes in tropospheric and stratospheric winds, temperature, and ozone over the Southern Hemisphere are examined. It is found that statistically significant trends similar to those of the Antarctic summer season are also observed since 1979 in austral fall, particularly May, and are strongest over the Pacific sector of the hemisphere. Evidence is provided for a significant shift in the position of the jet in May over the Pacific, and it is shown that the strengthening and shifting of the jet has rendered the latitudinal distribution of upper-tropospheric zonal wind more bimodal. The Antarctic ozone hole has cooled the lower stratosphere and strengthened the polar vortex. While the mechanism and timing are not fully understood, the ozone hole has been identified as a key driver of the summer season tropospheric circulation changes in several previous observational and modeling studies. It is found here that significant ozone depletion and associated polar cooling also occur in the lower most stratosphere and tropopause region through austral fall, with spatial patterns that are coincident with the observed changes in stratospheric circulation. It is also shown that radiatively driven temperature changes associated with the observed ozone depletion in May represent a substantial portion of the observed May cooling in the lowermost stratosphere, suggesting a potential for contribution to the circulation changes. |
author2 |
Ivy, Diane J. (author) Hilgenbrink, Casey (author) Kinnison, Doug (author) Alan Plumb, R. (author) Sheshadri, Aditi (author) Solomon, Susan (author) Thompson, David W. J. (author) |
format |
Article in Journal/Newspaper |
title |
Observed changes in the southern hemispheric circulation in May |
spellingShingle |
Observed changes in the southern hemispheric circulation in May |
title_short |
Observed changes in the southern hemispheric circulation in May |
title_full |
Observed changes in the southern hemispheric circulation in May |
title_fullStr |
Observed changes in the southern hemispheric circulation in May |
title_full_unstemmed |
Observed changes in the southern hemispheric circulation in May |
title_sort |
observed changes in the southern hemispheric circulation in may |
publishDate |
2017 |
url |
https://doi.org/10.1175/JCLI-D-16-0394.1 |
geographic |
Antarctic Austral Pacific The Antarctic |
geographic_facet |
Antarctic Austral Pacific The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
Journal of Climate--J. Climate--0894-8755--1520-0442 articles:19460 ark:/85065/d7xs5x5r doi:10.1175/JCLI-D-16-0394.1 |
op_rights |
Copyright 2017 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be "fair use" under Section 107 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Law (17 USC, as revised by P.L. 94-553) does not require the Society's permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statements, requires written permission or license from the AMS. Additional details are provided in the AMS Copyright Policies, available from the AMS at 617-227-2425 or amspubs@ametsoc.org. Permission to place a copy of this work on this server has been provided by the AMS. The AMS does not guarantee that the copy provided here is an accurate copy of the published work. |
op_doi |
https://doi.org/10.1175/JCLI-D-16-0394.1 |
container_title |
Journal of Climate |
container_volume |
30 |
container_issue |
2 |
container_start_page |
527 |
op_container_end_page |
536 |
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1776200047404253184 |