Observational evidence of energetic particle precipitation NOx (EPP-NOx) interaction with chlorine curbing Antarctic ozone loss
We investigate the impact of the so-called energetic particle precipitation (EPP) indirect effect on lower stratospheric ozone, ClO , and ClONO 2 in the Antarctic springtime. We use observations from the Microwave Limb Sounder (MLS) and Ozone Monitoring Instrument (OMI) on Aura, the Atmospheric Chem...
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ftcopernicus:oai:publications.copernicus.org:acp88512 2023-05-15T13:31:40+02:00 Observational evidence of energetic particle precipitation NOx (EPP-NOx) interaction with chlorine curbing Antarctic ozone loss Gordon, Emily M. Seppälä, Annika Funke, Bernd Tamminen, Johanna Walker, Kaley A. 2021-02-24 application/pdf https://doi.org/10.5194/acp-21-2819-2021 https://acp.copernicus.org/articles/21/2819/2021/ eng eng doi:10.5194/acp-21-2819-2021 https://acp.copernicus.org/articles/21/2819/2021/ eISSN: 1680-7324 Text 2021 ftcopernicus https://doi.org/10.5194/acp-21-2819-2021 2021-03-01T17:22:14Z We investigate the impact of the so-called energetic particle precipitation (EPP) indirect effect on lower stratospheric ozone, ClO , and ClONO 2 in the Antarctic springtime. We use observations from the Microwave Limb Sounder (MLS) and Ozone Monitoring Instrument (OMI) on Aura, the Atmospheric Chemistry Experiment – Fourier Transform Spectrometer (ACE-FTS) on SCISAT, and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on Envisat, covering the period from 2005 to 2017. Using the geomagnetic activity index Ap as a proxy for EPP, we find consistent ozone increases with elevated EPP during years with an easterly phase of the quasi-biennial oscillation (QBO) in both OMI and MLS observations. While these increases are the opposite of what has previously been reported at higher altitudes, the pattern in the MLS O 3 follows the typical descent patterns of EPP- NO x . The ozone enhancements are also present in the OMI total O 3 column observations. Analogous to the descent patterns found in O 3 , we also found consistent decreases in springtime MLS ClO following winters with elevated EPP. To verify if this is due to a previously proposed mechanism involving the conversion of ClO to the reservoir species ClONO 2 in reaction with NO 2 , we used ClONO 2 observations from ACE-FTS and MIPAS. As ClO and NO 2 are both catalysts in ozone destruction, the conversion to ClONO 2 would result in an ozone increase. We find a positive correlation between EPP and ClONO 2 in the upper stratosphere in the early spring and in the lower stratosphere in late spring, providing the first observational evidence supporting the previously proposed mechanism relating to EPP- NO x modulating Cl x -driven ozone loss. Our findings suggest that EPP has played an important role in modulating ozone depletion in the last 15 years. As chlorine loading in the polar stratosphere continues to decrease in the future, this buffering mechanism will become less effective, and catalytic ozone destruction by EPP- NO x will likely become a major contributor to Antarctic ozone loss. Text Antarc* Antarctic Copernicus Publications: E-Journals Antarctic The Antarctic Atmospheric Chemistry and Physics 21 4 2819 2836 |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
We investigate the impact of the so-called energetic particle precipitation (EPP) indirect effect on lower stratospheric ozone, ClO , and ClONO 2 in the Antarctic springtime. We use observations from the Microwave Limb Sounder (MLS) and Ozone Monitoring Instrument (OMI) on Aura, the Atmospheric Chemistry Experiment – Fourier Transform Spectrometer (ACE-FTS) on SCISAT, and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on Envisat, covering the period from 2005 to 2017. Using the geomagnetic activity index Ap as a proxy for EPP, we find consistent ozone increases with elevated EPP during years with an easterly phase of the quasi-biennial oscillation (QBO) in both OMI and MLS observations. While these increases are the opposite of what has previously been reported at higher altitudes, the pattern in the MLS O 3 follows the typical descent patterns of EPP- NO x . The ozone enhancements are also present in the OMI total O 3 column observations. Analogous to the descent patterns found in O 3 , we also found consistent decreases in springtime MLS ClO following winters with elevated EPP. To verify if this is due to a previously proposed mechanism involving the conversion of ClO to the reservoir species ClONO 2 in reaction with NO 2 , we used ClONO 2 observations from ACE-FTS and MIPAS. As ClO and NO 2 are both catalysts in ozone destruction, the conversion to ClONO 2 would result in an ozone increase. We find a positive correlation between EPP and ClONO 2 in the upper stratosphere in the early spring and in the lower stratosphere in late spring, providing the first observational evidence supporting the previously proposed mechanism relating to EPP- NO x modulating Cl x -driven ozone loss. Our findings suggest that EPP has played an important role in modulating ozone depletion in the last 15 years. As chlorine loading in the polar stratosphere continues to decrease in the future, this buffering mechanism will become less effective, and catalytic ozone destruction by EPP- NO x will likely become a major contributor to Antarctic ozone loss. |
format |
Text |
author |
Gordon, Emily M. Seppälä, Annika Funke, Bernd Tamminen, Johanna Walker, Kaley A. |
spellingShingle |
Gordon, Emily M. Seppälä, Annika Funke, Bernd Tamminen, Johanna Walker, Kaley A. Observational evidence of energetic particle precipitation NOx (EPP-NOx) interaction with chlorine curbing Antarctic ozone loss |
author_facet |
Gordon, Emily M. Seppälä, Annika Funke, Bernd Tamminen, Johanna Walker, Kaley A. |
author_sort |
Gordon, Emily M. |
title |
Observational evidence of energetic particle precipitation NOx (EPP-NOx) interaction with chlorine curbing Antarctic ozone loss |
title_short |
Observational evidence of energetic particle precipitation NOx (EPP-NOx) interaction with chlorine curbing Antarctic ozone loss |
title_full |
Observational evidence of energetic particle precipitation NOx (EPP-NOx) interaction with chlorine curbing Antarctic ozone loss |
title_fullStr |
Observational evidence of energetic particle precipitation NOx (EPP-NOx) interaction with chlorine curbing Antarctic ozone loss |
title_full_unstemmed |
Observational evidence of energetic particle precipitation NOx (EPP-NOx) interaction with chlorine curbing Antarctic ozone loss |
title_sort |
observational evidence of energetic particle precipitation nox (epp-nox) interaction with chlorine curbing antarctic ozone loss |
publishDate |
2021 |
url |
https://doi.org/10.5194/acp-21-2819-2021 https://acp.copernicus.org/articles/21/2819/2021/ |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
eISSN: 1680-7324 |
op_relation |
doi:10.5194/acp-21-2819-2021 https://acp.copernicus.org/articles/21/2819/2021/ |
op_doi |
https://doi.org/10.5194/acp-21-2819-2021 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
21 |
container_issue |
4 |
container_start_page |
2819 |
op_container_end_page |
2836 |
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1766020026498809856 |