Coherence between radar observations of magnetospheric field line resonances and discrete oscillations in the solar wind
Field line resonances have been observed for decades by ground-based and in situ instruments. The driving mechanism(s) are still unclear, although previous work has provided strong grounds that coherent waves in the solar wind may be a source. Here we present further evidence, with the use of multit...
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ftdoajarticles:oai:doaj.org/article:6cdd24c3abdd45c994491c5161372bac 2023-05-15T13:31:06+02:00 Coherence between radar observations of magnetospheric field line resonances and discrete oscillations in the solar wind J. A. E. Stephenson A. D. M. Walker 2010-01-01T00:00:00Z https://doi.org/10.5194/angeo-28-47-2010 https://doaj.org/article/6cdd24c3abdd45c994491c5161372bac EN eng Copernicus Publications https://www.ann-geophys.net/28/47/2010/angeo-28-47-2010.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-28-47-2010 0992-7689 1432-0576 https://doaj.org/article/6cdd24c3abdd45c994491c5161372bac Annales Geophysicae, Vol 28, Pp 47-59 (2010) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2010 ftdoajarticles https://doi.org/10.5194/angeo-28-47-2010 2022-12-31T12:18:47Z Field line resonances have been observed for decades by ground-based and in situ instruments. The driving mechanism(s) are still unclear, although previous work has provided strong grounds that coherent waves in the solar wind may be a source. Here we present further evidence, with the use of multitaper analysis, a sophisticated spectrum estimation technique. A set of windows (dpss tapers) is chosen with characteristics that best suit the width of the narrowband peaks to be identified. The orthogonality of the windows allows for a confidence level (of say 95%) against a null hypothesis of a noisy spectrum, so that significant peaks can be identified. Employing multitaper analysis we can determine the phase and amplitude coherence at the sampling rate of the data sets and, over their entire duration. These characteristics make this technique superior to single windowing or wavelet analysis. A high degree of phase and amplitude (greater then 95%) coherence is demonstrated between a 2.1 mHz field line resonance observed by the SHARE radar at Sanae, Antarctica and the solar wind oscillation detected by WIND and ACE satellites. Article in Journal/Newspaper Antarc* Antarctica Directory of Open Access Journals: DOAJ Articles SANAE ENVELOPE(-2.850,-2.850,-71.667,-71.667) Annales Geophysicae 28 1 47 59 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
spellingShingle |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 J. A. E. Stephenson A. D. M. Walker Coherence between radar observations of magnetospheric field line resonances and discrete oscillations in the solar wind |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
Field line resonances have been observed for decades by ground-based and in situ instruments. The driving mechanism(s) are still unclear, although previous work has provided strong grounds that coherent waves in the solar wind may be a source. Here we present further evidence, with the use of multitaper analysis, a sophisticated spectrum estimation technique. A set of windows (dpss tapers) is chosen with characteristics that best suit the width of the narrowband peaks to be identified. The orthogonality of the windows allows for a confidence level (of say 95%) against a null hypothesis of a noisy spectrum, so that significant peaks can be identified. Employing multitaper analysis we can determine the phase and amplitude coherence at the sampling rate of the data sets and, over their entire duration. These characteristics make this technique superior to single windowing or wavelet analysis. A high degree of phase and amplitude (greater then 95%) coherence is demonstrated between a 2.1 mHz field line resonance observed by the SHARE radar at Sanae, Antarctica and the solar wind oscillation detected by WIND and ACE satellites. |
format |
Article in Journal/Newspaper |
author |
J. A. E. Stephenson A. D. M. Walker |
author_facet |
J. A. E. Stephenson A. D. M. Walker |
author_sort |
J. A. E. Stephenson |
title |
Coherence between radar observations of magnetospheric field line resonances and discrete oscillations in the solar wind |
title_short |
Coherence between radar observations of magnetospheric field line resonances and discrete oscillations in the solar wind |
title_full |
Coherence between radar observations of magnetospheric field line resonances and discrete oscillations in the solar wind |
title_fullStr |
Coherence between radar observations of magnetospheric field line resonances and discrete oscillations in the solar wind |
title_full_unstemmed |
Coherence between radar observations of magnetospheric field line resonances and discrete oscillations in the solar wind |
title_sort |
coherence between radar observations of magnetospheric field line resonances and discrete oscillations in the solar wind |
publisher |
Copernicus Publications |
publishDate |
2010 |
url |
https://doi.org/10.5194/angeo-28-47-2010 https://doaj.org/article/6cdd24c3abdd45c994491c5161372bac |
long_lat |
ENVELOPE(-2.850,-2.850,-71.667,-71.667) |
geographic |
SANAE |
geographic_facet |
SANAE |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Annales Geophysicae, Vol 28, Pp 47-59 (2010) |
op_relation |
https://www.ann-geophys.net/28/47/2010/angeo-28-47-2010.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-28-47-2010 0992-7689 1432-0576 https://doaj.org/article/6cdd24c3abdd45c994491c5161372bac |
op_doi |
https://doi.org/10.5194/angeo-28-47-2010 |
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Annales Geophysicae |
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28 |
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1 |
container_start_page |
47 |
op_container_end_page |
59 |
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1766015990431219712 |