20 years of ClO measurements in the Antarctic lower stratosphere
We present 20 years (1996–2015) of austral springtime measurements of chlorine monoxide (ClO) over Antarctica from the Chlorine Oxide Experiment (ChlOE1) ground-based millimeter wave spectrometer at Scott Base, Antarctica, as well 12 years (2004–2015) of ClO measurements from the Aura Microwave Limb...
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ftdoajarticles:oai:doaj.org/article:16fae86d2be742738908452638ac9ac3 2023-05-15T13:40:45+02:00 20 years of ClO measurements in the Antarctic lower stratosphere G. E. Nedoluha B. J. Connor T. Mooney J. W. Barrett A. Parrish R. M. Gomez I. Boyd D. R. Allen M. Kotkamp S. Kremser T. Deshler P. Newman M. L. Santee 2016-08-01T00:00:00Z https://doi.org/10.5194/acp-16-10725-2016 https://doaj.org/article/16fae86d2be742738908452638ac9ac3 EN eng Copernicus Publications https://www.atmos-chem-phys.net/16/10725/2016/acp-16-10725-2016.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-16-10725-2016 1680-7316 1680-7324 https://doaj.org/article/16fae86d2be742738908452638ac9ac3 Atmospheric Chemistry and Physics, Vol 16, Pp 10725-10734 (2016) Physics QC1-999 Chemistry QD1-999 article 2016 ftdoajarticles https://doi.org/10.5194/acp-16-10725-2016 2022-12-30T21:33:21Z We present 20 years (1996–2015) of austral springtime measurements of chlorine monoxide (ClO) over Antarctica from the Chlorine Oxide Experiment (ChlOE1) ground-based millimeter wave spectrometer at Scott Base, Antarctica, as well 12 years (2004–2015) of ClO measurements from the Aura Microwave Limb Sounder (MLS). From August onwards we observe a strong increase in lower stratospheric ClO, with a peak column amount usually occurring in early September. From mid-September onwards we observe a strong decrease in ClO. In order to study interannual differences, we focus on a 3-week period from 28 August to 17 September for each year and compare the average column ClO anomalies. These column ClO anomalies are shown to be highly correlated with the average ozone mass deficit for September and October of each year. We also show that anomalies in column ClO are strongly anti-correlated with 30 hPa temperature anomalies, both on a daily and an interannual timescale. Making use of this anti-correlation we calculate the linear dependence of the interannual variations in column ClO on interannual variations in temperature. By making use of this relationship, we can better estimate the underlying trend in the total chlorine (Cl y = HCl + ClONO 2 + HOCl + 2 × Cl 2 + 2 × Cl 2 O 2 + ClO + Cl). The resultant trends in Cl y , which determine the long-term trend in ClO, are estimated to be −0.5 ± 0.2, −1.4 ± 0.9, and −0.6 ± 0.4 % year −1 , for zonal MLS, Scott Base MLS (both 2004–2015), and ChlOE (1996–2015) respectively. These trends are within 1 σ of trends in stratospheric Cl y previously found at other latitudes. The decrease in ClO is consistent with the trend expected from regulations enacted under the Montreal Protocol. Article in Journal/Newspaper Antarc* Antarctic Antarctica Directory of Open Access Journals: DOAJ Articles Antarctic Austral Scott Base ENVELOPE(166.766,166.766,-77.849,-77.849) The Antarctic Atmospheric Chemistry and Physics 16 16 10725 10734 |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
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language |
English |
topic |
Physics QC1-999 Chemistry QD1-999 |
spellingShingle |
Physics QC1-999 Chemistry QD1-999 G. E. Nedoluha B. J. Connor T. Mooney J. W. Barrett A. Parrish R. M. Gomez I. Boyd D. R. Allen M. Kotkamp S. Kremser T. Deshler P. Newman M. L. Santee 20 years of ClO measurements in the Antarctic lower stratosphere |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
We present 20 years (1996–2015) of austral springtime measurements of chlorine monoxide (ClO) over Antarctica from the Chlorine Oxide Experiment (ChlOE1) ground-based millimeter wave spectrometer at Scott Base, Antarctica, as well 12 years (2004–2015) of ClO measurements from the Aura Microwave Limb Sounder (MLS). From August onwards we observe a strong increase in lower stratospheric ClO, with a peak column amount usually occurring in early September. From mid-September onwards we observe a strong decrease in ClO. In order to study interannual differences, we focus on a 3-week period from 28 August to 17 September for each year and compare the average column ClO anomalies. These column ClO anomalies are shown to be highly correlated with the average ozone mass deficit for September and October of each year. We also show that anomalies in column ClO are strongly anti-correlated with 30 hPa temperature anomalies, both on a daily and an interannual timescale. Making use of this anti-correlation we calculate the linear dependence of the interannual variations in column ClO on interannual variations in temperature. By making use of this relationship, we can better estimate the underlying trend in the total chlorine (Cl y = HCl + ClONO 2 + HOCl + 2 × Cl 2 + 2 × Cl 2 O 2 + ClO + Cl). The resultant trends in Cl y , which determine the long-term trend in ClO, are estimated to be −0.5 ± 0.2, −1.4 ± 0.9, and −0.6 ± 0.4 % year −1 , for zonal MLS, Scott Base MLS (both 2004–2015), and ChlOE (1996–2015) respectively. These trends are within 1 σ of trends in stratospheric Cl y previously found at other latitudes. The decrease in ClO is consistent with the trend expected from regulations enacted under the Montreal Protocol. |
format |
Article in Journal/Newspaper |
author |
G. E. Nedoluha B. J. Connor T. Mooney J. W. Barrett A. Parrish R. M. Gomez I. Boyd D. R. Allen M. Kotkamp S. Kremser T. Deshler P. Newman M. L. Santee |
author_facet |
G. E. Nedoluha B. J. Connor T. Mooney J. W. Barrett A. Parrish R. M. Gomez I. Boyd D. R. Allen M. Kotkamp S. Kremser T. Deshler P. Newman M. L. Santee |
author_sort |
G. E. Nedoluha |
title |
20 years of ClO measurements in the Antarctic lower stratosphere |
title_short |
20 years of ClO measurements in the Antarctic lower stratosphere |
title_full |
20 years of ClO measurements in the Antarctic lower stratosphere |
title_fullStr |
20 years of ClO measurements in the Antarctic lower stratosphere |
title_full_unstemmed |
20 years of ClO measurements in the Antarctic lower stratosphere |
title_sort |
20 years of clo measurements in the antarctic lower stratosphere |
publisher |
Copernicus Publications |
publishDate |
2016 |
url |
https://doi.org/10.5194/acp-16-10725-2016 https://doaj.org/article/16fae86d2be742738908452638ac9ac3 |
long_lat |
ENVELOPE(166.766,166.766,-77.849,-77.849) |
geographic |
Antarctic Austral Scott Base The Antarctic |
geographic_facet |
Antarctic Austral Scott Base The Antarctic |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
Atmospheric Chemistry and Physics, Vol 16, Pp 10725-10734 (2016) |
op_relation |
https://www.atmos-chem-phys.net/16/10725/2016/acp-16-10725-2016.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-16-10725-2016 1680-7316 1680-7324 https://doaj.org/article/16fae86d2be742738908452638ac9ac3 |
op_doi |
https://doi.org/10.5194/acp-16-10725-2016 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
16 |
container_issue |
16 |
container_start_page |
10725 |
op_container_end_page |
10734 |
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1766139387373944832 |