Latitudinal extent of the January 2005 solar proton event in the Northern Hemisphere from satellite observations of hydroxyl
We utilise hydroxyl observations from the MLS/Aura satellite instrument to study the latitudinal extent of particle forcing in the northern polar region during the January 2005 solar proton event. MLS is the first satellite instrument to observe HO x changes during such an event. We also predict the...
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ftdoajarticles:oai:doaj.org/article:56a90c1bfd9145c98bb88b51048647cb 2023-05-15T18:20:18+02:00 Latitudinal extent of the January 2005 solar proton event in the Northern Hemisphere from satellite observations of hydroxyl P. T. Verronen C. J. Rodger M. A. Clilverd H. M. Pickett E. Turunen 2007-11-01T00:00:00Z https://doi.org/10.5194/angeo-25-2203-2007 https://doaj.org/article/56a90c1bfd9145c98bb88b51048647cb EN eng Copernicus Publications https://www.ann-geophys.net/25/2203/2007/angeo-25-2203-2007.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-25-2203-2007 0992-7689 1432-0576 https://doaj.org/article/56a90c1bfd9145c98bb88b51048647cb Annales Geophysicae, Vol 25, Pp 2203-2215 (2007) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2007 ftdoajarticles https://doi.org/10.5194/angeo-25-2203-2007 2022-12-30T23:47:53Z We utilise hydroxyl observations from the MLS/Aura satellite instrument to study the latitudinal extent of particle forcing in the northern polar region during the January 2005 solar proton event. MLS is the first satellite instrument to observe HO x changes during such an event. We also predict the hydroxyl changes with respect to the magnetic latitude by the Sodankylä Ion and Neutral Chemistry model, estimating the variable magnetic cutoff energies for protons using a parameterisation based on magnetosphere modelling and the planetary magnetic index K p . In the middle and lower mesosphere, HO x species are good indicators of the changes in the atmosphere during solar proton events, because they respond rapidly to both increases and decreases in proton forcing. Also, atmospheric transport has a negligible effect on HO x because of its short chemical lifetime. The observations indicate the boundary of the proton forcing and a transition region, from none to the "full" effect, which ranges from about 57 to 64 degrees of magnetic latitude. When saturating the rigidity cutoff K p at 6 in the model, as suggested by earlier studies using observations of cosmic radio noise absorption, the equatorward boundary of the transition region is offset by ≈2 degrees polewards compared with the data, thus the latitudinal extent of the proton forcing in the atmosphere is underestimated. However, the model predictions are in reasonable agreement with the MLS measurements when the K p index is allowed to vary within its nominal range, i.e., from 1 to 9 in the cutoff calculation. Article in Journal/Newspaper Sodankylä Directory of Open Access Journals: DOAJ Articles Sodankylä ENVELOPE(26.600,26.600,67.417,67.417) Annales Geophysicae 25 10 2203 2215 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
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English |
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Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
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Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 P. T. Verronen C. J. Rodger M. A. Clilverd H. M. Pickett E. Turunen Latitudinal extent of the January 2005 solar proton event in the Northern Hemisphere from satellite observations of hydroxyl |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
We utilise hydroxyl observations from the MLS/Aura satellite instrument to study the latitudinal extent of particle forcing in the northern polar region during the January 2005 solar proton event. MLS is the first satellite instrument to observe HO x changes during such an event. We also predict the hydroxyl changes with respect to the magnetic latitude by the Sodankylä Ion and Neutral Chemistry model, estimating the variable magnetic cutoff energies for protons using a parameterisation based on magnetosphere modelling and the planetary magnetic index K p . In the middle and lower mesosphere, HO x species are good indicators of the changes in the atmosphere during solar proton events, because they respond rapidly to both increases and decreases in proton forcing. Also, atmospheric transport has a negligible effect on HO x because of its short chemical lifetime. The observations indicate the boundary of the proton forcing and a transition region, from none to the "full" effect, which ranges from about 57 to 64 degrees of magnetic latitude. When saturating the rigidity cutoff K p at 6 in the model, as suggested by earlier studies using observations of cosmic radio noise absorption, the equatorward boundary of the transition region is offset by ≈2 degrees polewards compared with the data, thus the latitudinal extent of the proton forcing in the atmosphere is underestimated. However, the model predictions are in reasonable agreement with the MLS measurements when the K p index is allowed to vary within its nominal range, i.e., from 1 to 9 in the cutoff calculation. |
format |
Article in Journal/Newspaper |
author |
P. T. Verronen C. J. Rodger M. A. Clilverd H. M. Pickett E. Turunen |
author_facet |
P. T. Verronen C. J. Rodger M. A. Clilverd H. M. Pickett E. Turunen |
author_sort |
P. T. Verronen |
title |
Latitudinal extent of the January 2005 solar proton event in the Northern Hemisphere from satellite observations of hydroxyl |
title_short |
Latitudinal extent of the January 2005 solar proton event in the Northern Hemisphere from satellite observations of hydroxyl |
title_full |
Latitudinal extent of the January 2005 solar proton event in the Northern Hemisphere from satellite observations of hydroxyl |
title_fullStr |
Latitudinal extent of the January 2005 solar proton event in the Northern Hemisphere from satellite observations of hydroxyl |
title_full_unstemmed |
Latitudinal extent of the January 2005 solar proton event in the Northern Hemisphere from satellite observations of hydroxyl |
title_sort |
latitudinal extent of the january 2005 solar proton event in the northern hemisphere from satellite observations of hydroxyl |
publisher |
Copernicus Publications |
publishDate |
2007 |
url |
https://doi.org/10.5194/angeo-25-2203-2007 https://doaj.org/article/56a90c1bfd9145c98bb88b51048647cb |
long_lat |
ENVELOPE(26.600,26.600,67.417,67.417) |
geographic |
Sodankylä |
geographic_facet |
Sodankylä |
genre |
Sodankylä |
genre_facet |
Sodankylä |
op_source |
Annales Geophysicae, Vol 25, Pp 2203-2215 (2007) |
op_relation |
https://www.ann-geophys.net/25/2203/2007/angeo-25-2203-2007.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-25-2203-2007 0992-7689 1432-0576 https://doaj.org/article/56a90c1bfd9145c98bb88b51048647cb |
op_doi |
https://doi.org/10.5194/angeo-25-2203-2007 |
container_title |
Annales Geophysicae |
container_volume |
25 |
container_issue |
10 |
container_start_page |
2203 |
op_container_end_page |
2215 |
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1766197820827631616 |