Response of the Antarctic stratosphere to warm pool El Niño Events in the GEOS CCM
The Goddard Earth Observing System Chemistry-Climate Model, Version 2 (GEOS V2 CCM) is used to investigate the response of the Antarctic stratosphere to (1) warm pool El Niño (WPEN) events and (2) the sensitivity of this response to the phase of the QBO. A new formulation of the GEOS V2 CCM includes...
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ftdoajarticles:oai:doaj.org/article:8f83d2c5366c4516b68b3360ff812b71 2023-05-15T13:47:24+02:00 Response of the Antarctic stratosphere to warm pool El Niño Events in the GEOS CCM M. M. Hurwitz I.-S. Song L. D. Oman P. A. Newman A. M. Molod S. M. Frith J. E. Nielsen 2011-09-01T00:00:00Z https://doi.org/10.5194/acp-11-9659-2011 https://doaj.org/article/8f83d2c5366c4516b68b3360ff812b71 EN eng Copernicus Publications http://www.atmos-chem-phys.net/11/9659/2011/acp-11-9659-2011.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-11-9659-2011 1680-7316 1680-7324 https://doaj.org/article/8f83d2c5366c4516b68b3360ff812b71 Atmospheric Chemistry and Physics, Vol 11, Iss 18, Pp 9659-9669 (2011) Physics QC1-999 Chemistry QD1-999 article 2011 ftdoajarticles https://doi.org/10.5194/acp-11-9659-2011 2022-12-31T01:36:30Z The Goddard Earth Observing System Chemistry-Climate Model, Version 2 (GEOS V2 CCM) is used to investigate the response of the Antarctic stratosphere to (1) warm pool El Niño (WPEN) events and (2) the sensitivity of this response to the phase of the QBO. A new formulation of the GEOS V2 CCM includes an improved general circulation model and an internally generated quasi-biennial oscillation (QBO). Two 50-yr time-slice simulations are forced by repeating annual cycles of sea surface temperatures and sea ice concentrations composited from observed WPEN and neutral ENSO (ENSON) events. In these simulations, greenhouse gas and ozone-depleting substance concentrations represent the present-day climate. The modelled responses to WPEN, and to the phase of the QBO during WPEN, are compared with NASA's Modern Era Retrospective-Analysis for Research and Applications (MERRA) reanalysis. WPEN events enhance poleward tropospheric planetary wave activity in the central South Pacific region during austral spring, leading to relative warming of the Antarctic lower stratosphere in November/December. During the easterly phase of the QBO (QBO-E), the GEOS V2 CCM reproduces the observed 4–5 K warming of the polar region at 50 hPa, in the WPEN simulation relative to ENSON. In the recent past, the response to WPEN events was sensitive to the phase of the QBO: the enhancement in planetary wave driving and the lower stratospheric warming signal were mainly associated with WPEN events coincident with QBO-E. In the GEOS V2 CCM, however, the Antarctic response to WPEN events is insensitive to the phase of the QBO: the modelled response is always easterly QBO-like. The QBO signal does not extend far enough into the lower stratosphere and upper troposphere to modulate convection and thus planetary wave activity in the south central Pacific. Article in Journal/Newspaper Antarc* Antarctic Sea ice Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic Austral Pacific Merra ENVELOPE(12.615,12.615,65.816,65.816) Atmospheric Chemistry and Physics 11 18 9659 9669 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Physics QC1-999 Chemistry QD1-999 |
spellingShingle |
Physics QC1-999 Chemistry QD1-999 M. M. Hurwitz I.-S. Song L. D. Oman P. A. Newman A. M. Molod S. M. Frith J. E. Nielsen Response of the Antarctic stratosphere to warm pool El Niño Events in the GEOS CCM |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
The Goddard Earth Observing System Chemistry-Climate Model, Version 2 (GEOS V2 CCM) is used to investigate the response of the Antarctic stratosphere to (1) warm pool El Niño (WPEN) events and (2) the sensitivity of this response to the phase of the QBO. A new formulation of the GEOS V2 CCM includes an improved general circulation model and an internally generated quasi-biennial oscillation (QBO). Two 50-yr time-slice simulations are forced by repeating annual cycles of sea surface temperatures and sea ice concentrations composited from observed WPEN and neutral ENSO (ENSON) events. In these simulations, greenhouse gas and ozone-depleting substance concentrations represent the present-day climate. The modelled responses to WPEN, and to the phase of the QBO during WPEN, are compared with NASA's Modern Era Retrospective-Analysis for Research and Applications (MERRA) reanalysis. WPEN events enhance poleward tropospheric planetary wave activity in the central South Pacific region during austral spring, leading to relative warming of the Antarctic lower stratosphere in November/December. During the easterly phase of the QBO (QBO-E), the GEOS V2 CCM reproduces the observed 4–5 K warming of the polar region at 50 hPa, in the WPEN simulation relative to ENSON. In the recent past, the response to WPEN events was sensitive to the phase of the QBO: the enhancement in planetary wave driving and the lower stratospheric warming signal were mainly associated with WPEN events coincident with QBO-E. In the GEOS V2 CCM, however, the Antarctic response to WPEN events is insensitive to the phase of the QBO: the modelled response is always easterly QBO-like. The QBO signal does not extend far enough into the lower stratosphere and upper troposphere to modulate convection and thus planetary wave activity in the south central Pacific. |
format |
Article in Journal/Newspaper |
author |
M. M. Hurwitz I.-S. Song L. D. Oman P. A. Newman A. M. Molod S. M. Frith J. E. Nielsen |
author_facet |
M. M. Hurwitz I.-S. Song L. D. Oman P. A. Newman A. M. Molod S. M. Frith J. E. Nielsen |
author_sort |
M. M. Hurwitz |
title |
Response of the Antarctic stratosphere to warm pool El Niño Events in the GEOS CCM |
title_short |
Response of the Antarctic stratosphere to warm pool El Niño Events in the GEOS CCM |
title_full |
Response of the Antarctic stratosphere to warm pool El Niño Events in the GEOS CCM |
title_fullStr |
Response of the Antarctic stratosphere to warm pool El Niño Events in the GEOS CCM |
title_full_unstemmed |
Response of the Antarctic stratosphere to warm pool El Niño Events in the GEOS CCM |
title_sort |
response of the antarctic stratosphere to warm pool el niño events in the geos ccm |
publisher |
Copernicus Publications |
publishDate |
2011 |
url |
https://doi.org/10.5194/acp-11-9659-2011 https://doaj.org/article/8f83d2c5366c4516b68b3360ff812b71 |
long_lat |
ENVELOPE(12.615,12.615,65.816,65.816) |
geographic |
Antarctic The Antarctic Austral Pacific Merra |
geographic_facet |
Antarctic The Antarctic Austral Pacific Merra |
genre |
Antarc* Antarctic Sea ice |
genre_facet |
Antarc* Antarctic Sea ice |
op_source |
Atmospheric Chemistry and Physics, Vol 11, Iss 18, Pp 9659-9669 (2011) |
op_relation |
http://www.atmos-chem-phys.net/11/9659/2011/acp-11-9659-2011.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-11-9659-2011 1680-7316 1680-7324 https://doaj.org/article/8f83d2c5366c4516b68b3360ff812b71 |
op_doi |
https://doi.org/10.5194/acp-11-9659-2011 |
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Atmospheric Chemistry and Physics |
container_volume |
11 |
container_issue |
18 |
container_start_page |
9659 |
op_container_end_page |
9669 |
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1766247066509508608 |