An unusual stratospheric ozone decrease in the Southern Hemisphere subtropics linked to isentropic air-mass transport as observed over Irene (25.5° S, 28.1° E) in mid-May 2002
International audience Abstract. A prominent ozone minimum of less than 240 Dobson Units (DU) was observed over Irene (25.5° S, 28.1° E), a subtropical site in the Southern Hemisphere, by the Total Ozone Mapping Spectrometer (TOMS) during May 2002 with an extremely low ozone value of less than 219 D...
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ftunivnantes:oai:HAL:hal-03695925v1 2023-05-15T13:41:39+02:00 An unusual stratospheric ozone decrease in the Southern Hemisphere subtropics linked to isentropic air-mass transport as observed over Irene (25.5° S, 28.1° E) in mid-May 2002 Semane, N. Bencherif, H. Morel, B. Hauchecorne, A. Diab, R. Université de La Réunion - Faculté des Sciences et Technologies (FST) Université de La Réunion (UR) 2006 https://hal.univ-reunion.fr/hal-03695925 https://doi.org/10.5194/acp-6-1927-2006 en eng HAL CCSD European Geosciences Union info:eu-repo/semantics/altIdentifier/doi/10.5194/acp-6-1927-2006 hal-03695925 https://hal.univ-reunion.fr/hal-03695925 doi:10.5194/acp-6-1927-2006 ISSN: 1680-7316 EISSN: 1680-7324 Atmospheric Chemistry and Physics https://hal.univ-reunion.fr/hal-03695925 Atmospheric Chemistry and Physics, European Geosciences Union, 2006, 6 (7), pp.1927-1936. ⟨10.5194/acp-6-1927-2006⟩ [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology info:eu-repo/semantics/article Journal articles 2006 ftunivnantes https://doi.org/10.5194/acp-6-1927-2006 2022-06-21T22:44:21Z International audience Abstract. A prominent ozone minimum of less than 240 Dobson Units (DU) was observed over Irene (25.5° S, 28.1° E), a subtropical site in the Southern Hemisphere, by the Total Ozone Mapping Spectrometer (TOMS) during May 2002 with an extremely low ozone value of less than 219 DU recorded on 12 May, as compared to the climatological mean value of 249 DU for May between 1999 and 2005. In this study, the vertical structure of this ozone minimum is examined using ozonesonde measurements performed over Irene on 15 May 2002, when the total ozone (as given by TOMS) was about 226 DU. It is shown that this ozone minimum is of Antarctic polar origin with a low-ozone layer in the middle stratosphere above 625 K (where the climatological ozone gradient points equatorward), and is of tropical origin with a low-ozone layer in the lower stratosphere between the 400-K and 450-K isentropic levels (where the climatological ozone gradient is reversed). The upper and lower depleted parts of the ozonesonde profile for 15 May are then respectively attributed to equatorward and poleward transport of low-ozone air toward the subtropics in the Southern Hemisphere. The tropical air moving over Irene and the polar one passing over the same area associated with enhanced planetary-wave activity are successfully simulated using the high-resolution advection contour model of Ertel's potential vorticity MIMOSA. The unusual distribution of ozone over Irene during May 2002 in the middle stratosphere is connected to the anomalously pre-conditioned structure of the polar vortex at that time of the year. The winter stratospheric wave driving leading to the ozone minimum is investigated by means of the Eliassen-Palm flux computed from the European Center for Medium-range Weather Forecasts (ECMWF) ERA40 re-analyses. Article in Journal/Newspaper Antarc* Antarctic Université de Nantes: HAL-UNIV-NANTES Antarctic Atmospheric Chemistry and Physics 6 7 1927 1936 |
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Open Polar |
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Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
spellingShingle |
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology Semane, N. Bencherif, H. Morel, B. Hauchecorne, A. Diab, R. An unusual stratospheric ozone decrease in the Southern Hemisphere subtropics linked to isentropic air-mass transport as observed over Irene (25.5° S, 28.1° E) in mid-May 2002 |
topic_facet |
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
description |
International audience Abstract. A prominent ozone minimum of less than 240 Dobson Units (DU) was observed over Irene (25.5° S, 28.1° E), a subtropical site in the Southern Hemisphere, by the Total Ozone Mapping Spectrometer (TOMS) during May 2002 with an extremely low ozone value of less than 219 DU recorded on 12 May, as compared to the climatological mean value of 249 DU for May between 1999 and 2005. In this study, the vertical structure of this ozone minimum is examined using ozonesonde measurements performed over Irene on 15 May 2002, when the total ozone (as given by TOMS) was about 226 DU. It is shown that this ozone minimum is of Antarctic polar origin with a low-ozone layer in the middle stratosphere above 625 K (where the climatological ozone gradient points equatorward), and is of tropical origin with a low-ozone layer in the lower stratosphere between the 400-K and 450-K isentropic levels (where the climatological ozone gradient is reversed). The upper and lower depleted parts of the ozonesonde profile for 15 May are then respectively attributed to equatorward and poleward transport of low-ozone air toward the subtropics in the Southern Hemisphere. The tropical air moving over Irene and the polar one passing over the same area associated with enhanced planetary-wave activity are successfully simulated using the high-resolution advection contour model of Ertel's potential vorticity MIMOSA. The unusual distribution of ozone over Irene during May 2002 in the middle stratosphere is connected to the anomalously pre-conditioned structure of the polar vortex at that time of the year. The winter stratospheric wave driving leading to the ozone minimum is investigated by means of the Eliassen-Palm flux computed from the European Center for Medium-range Weather Forecasts (ECMWF) ERA40 re-analyses. |
author2 |
Université de La Réunion - Faculté des Sciences et Technologies (FST) Université de La Réunion (UR) |
format |
Article in Journal/Newspaper |
author |
Semane, N. Bencherif, H. Morel, B. Hauchecorne, A. Diab, R. |
author_facet |
Semane, N. Bencherif, H. Morel, B. Hauchecorne, A. Diab, R. |
author_sort |
Semane, N. |
title |
An unusual stratospheric ozone decrease in the Southern Hemisphere subtropics linked to isentropic air-mass transport as observed over Irene (25.5° S, 28.1° E) in mid-May 2002 |
title_short |
An unusual stratospheric ozone decrease in the Southern Hemisphere subtropics linked to isentropic air-mass transport as observed over Irene (25.5° S, 28.1° E) in mid-May 2002 |
title_full |
An unusual stratospheric ozone decrease in the Southern Hemisphere subtropics linked to isentropic air-mass transport as observed over Irene (25.5° S, 28.1° E) in mid-May 2002 |
title_fullStr |
An unusual stratospheric ozone decrease in the Southern Hemisphere subtropics linked to isentropic air-mass transport as observed over Irene (25.5° S, 28.1° E) in mid-May 2002 |
title_full_unstemmed |
An unusual stratospheric ozone decrease in the Southern Hemisphere subtropics linked to isentropic air-mass transport as observed over Irene (25.5° S, 28.1° E) in mid-May 2002 |
title_sort |
unusual stratospheric ozone decrease in the southern hemisphere subtropics linked to isentropic air-mass transport as observed over irene (25.5° s, 28.1° e) in mid-may 2002 |
publisher |
HAL CCSD |
publishDate |
2006 |
url |
https://hal.univ-reunion.fr/hal-03695925 https://doi.org/10.5194/acp-6-1927-2006 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
ISSN: 1680-7316 EISSN: 1680-7324 Atmospheric Chemistry and Physics https://hal.univ-reunion.fr/hal-03695925 Atmospheric Chemistry and Physics, European Geosciences Union, 2006, 6 (7), pp.1927-1936. ⟨10.5194/acp-6-1927-2006⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/acp-6-1927-2006 hal-03695925 https://hal.univ-reunion.fr/hal-03695925 doi:10.5194/acp-6-1927-2006 |
op_doi |
https://doi.org/10.5194/acp-6-1927-2006 |
container_title |
Atmospheric Chemistry and Physics |
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6 |
container_issue |
7 |
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1927 |
op_container_end_page |
1936 |
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1766153615043461120 |