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...
Published in: | Journal of Climate |
---|---|
Main Authors: | , , , , , , |
Other Authors: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Meteorological Society
2016
|
Subjects: | |
Online Access: | http://hdl.handle.net/1721.1/111192 |
id |
ftmit:oai:dspace.mit.edu:1721.1/111192 |
---|---|
record_format |
openpolar |
spelling |
ftmit:oai:dspace.mit.edu:1721.1/111192 2023-06-11T04:07:05+02:00 Observed Changes in the Southern Hemispheric Circulation in May Hilgenbrink, Casey Kinnison, Doug Alan Plumb, R. Sheshadri, Aditi Thompson, David W. J. Ivy, Diane J Solomon, Susan Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Ivy, Diane J Solomon, Susan 2016-05 application/pdf http://hdl.handle.net/1721.1/111192 en_US eng American Meteorological Society http://dx.doi.org/10.1175/jcli-d-16-0394.1 Journal of Climate 0894-8755 1520-0442 http://hdl.handle.net/1721.1/111192 Ivy, Diane J. et al. “Observed Changes in the Southern Hemispheric Circulation in May.” Journal of Climate 30, 2 (January 2017): 527–536 © 2017 American Meteorological Society orcid:0000-0002-2020-7581 Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. American Meteorological Society Article http://purl.org/eprint/type/JournalArticle 2016 ftmit https://doi.org/10.1175/jcli-d-16-0394.1 2023-05-29T08:34:16Z 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 lowermost 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. National Science Foundation (U.S.) (Grant 1419667) Article in Journal/Newspaper Antarc* Antarctic DSpace@MIT (Massachusetts Institute of Technology) Antarctic The Antarctic Austral Pacific Journal of Climate 30 2 527 536 |
institution |
Open Polar |
collection |
DSpace@MIT (Massachusetts Institute of Technology) |
op_collection_id |
ftmit |
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 lowermost 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. National Science Foundation (U.S.) (Grant 1419667) |
author2 |
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Ivy, Diane J Solomon, Susan |
format |
Article in Journal/Newspaper |
author |
Hilgenbrink, Casey Kinnison, Doug Alan Plumb, R. Sheshadri, Aditi Thompson, David W. J. Ivy, Diane J Solomon, Susan |
spellingShingle |
Hilgenbrink, Casey Kinnison, Doug Alan Plumb, R. Sheshadri, Aditi Thompson, David W. J. Ivy, Diane J Solomon, Susan Observed Changes in the Southern Hemispheric Circulation in May |
author_facet |
Hilgenbrink, Casey Kinnison, Doug Alan Plumb, R. Sheshadri, Aditi Thompson, David W. J. Ivy, Diane J Solomon, Susan |
author_sort |
Hilgenbrink, Casey |
title |
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 |
publisher |
American Meteorological Society |
publishDate |
2016 |
url |
http://hdl.handle.net/1721.1/111192 |
geographic |
Antarctic The Antarctic Austral Pacific |
geographic_facet |
Antarctic The Antarctic Austral Pacific |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
American Meteorological Society |
op_relation |
http://dx.doi.org/10.1175/jcli-d-16-0394.1 Journal of Climate 0894-8755 1520-0442 http://hdl.handle.net/1721.1/111192 Ivy, Diane J. et al. “Observed Changes in the Southern Hemispheric Circulation in May.” Journal of Climate 30, 2 (January 2017): 527–536 © 2017 American Meteorological Society orcid:0000-0002-2020-7581 |
op_rights |
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. |
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 |
_version_ |
1768379701823275008 |