Comparison of the open-closed field line boundary location inferred using IMAGE-FUV SI12 images and EISCAT radar observations
We compare the location of the polar cap boundary (PCB) determined using two different techniques, and use them as proxies for the open-closed field line boundary (OCB). Electron temperatures from observations of the EISCAT radar facility are used to estimate the latitude of the PCB along the meridi...
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ftdoajarticles:oai:doaj.org/article:4edd7a8754354a4ab504f76b31dd351e 2023-05-15T16:04:23+02:00 Comparison of the open-closed field line boundary location inferred using IMAGE-FUV SI12 images and EISCAT radar observations B. Hubert A. T. Aikio O. Amm T. Pitkänen K. Kauristie S. E. Milan S. W. H. Cowley J.-C. Gérard 2010-04-01T00:00:00Z https://doi.org/10.5194/angeo-28-883-2010 https://doaj.org/article/4edd7a8754354a4ab504f76b31dd351e EN eng Copernicus Publications https://www.ann-geophys.net/28/883/2010/angeo-28-883-2010.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-28-883-2010 0992-7689 1432-0576 https://doaj.org/article/4edd7a8754354a4ab504f76b31dd351e Annales Geophysicae, Vol 28, Pp 883-892 (2010) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2010 ftdoajarticles https://doi.org/10.5194/angeo-28-883-2010 2022-12-30T23:35:15Z We compare the location of the polar cap boundary (PCB) determined using two different techniques, and use them as proxies for the open-closed field line boundary (OCB). Electron temperatures from observations of the EISCAT radar facility are used to estimate the latitude of the PCB along the meridian of the EISCAT VHF beam. The second method utilizes global images of proton aurora obtained by the IMAGE satellite FUV SI12 instrument. These methods are applied to three different intervals. In two events, the agreement between the methods is good and the mean of the difference is within the resolution of the observations. In a third event, the PCB estimated from EISCAT data is located several degrees poleward of that obtained from the IMAGE FUV SI12 instrument. Comparison of the reconnection electric field estimated from the two methods shows that high-resolution measurements both in time and space are needed to capture the variations in reconnection electric field during substorm expansion. In addition to the two techniques introduced above to determine the PCB location, we also use a search for the location of the reversal of the east-west component of the equivalent current known as the magnetic convection reversal boundary (MCRB). The MCRB from the MIRACLE magnetometer chain mainly follows the motion of the polar cap boundary during different substorm phases, but differences arise near the Harang discontinuity. Article in Journal/Newspaper EISCAT Directory of Open Access Journals: DOAJ Articles Annales Geophysicae 28 4 883 892 |
institution |
Open Polar |
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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 B. Hubert A. T. Aikio O. Amm T. Pitkänen K. Kauristie S. E. Milan S. W. H. Cowley J.-C. Gérard Comparison of the open-closed field line boundary location inferred using IMAGE-FUV SI12 images and EISCAT radar observations |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
We compare the location of the polar cap boundary (PCB) determined using two different techniques, and use them as proxies for the open-closed field line boundary (OCB). Electron temperatures from observations of the EISCAT radar facility are used to estimate the latitude of the PCB along the meridian of the EISCAT VHF beam. The second method utilizes global images of proton aurora obtained by the IMAGE satellite FUV SI12 instrument. These methods are applied to three different intervals. In two events, the agreement between the methods is good and the mean of the difference is within the resolution of the observations. In a third event, the PCB estimated from EISCAT data is located several degrees poleward of that obtained from the IMAGE FUV SI12 instrument. Comparison of the reconnection electric field estimated from the two methods shows that high-resolution measurements both in time and space are needed to capture the variations in reconnection electric field during substorm expansion. In addition to the two techniques introduced above to determine the PCB location, we also use a search for the location of the reversal of the east-west component of the equivalent current known as the magnetic convection reversal boundary (MCRB). The MCRB from the MIRACLE magnetometer chain mainly follows the motion of the polar cap boundary during different substorm phases, but differences arise near the Harang discontinuity. |
format |
Article in Journal/Newspaper |
author |
B. Hubert A. T. Aikio O. Amm T. Pitkänen K. Kauristie S. E. Milan S. W. H. Cowley J.-C. Gérard |
author_facet |
B. Hubert A. T. Aikio O. Amm T. Pitkänen K. Kauristie S. E. Milan S. W. H. Cowley J.-C. Gérard |
author_sort |
B. Hubert |
title |
Comparison of the open-closed field line boundary location inferred using IMAGE-FUV SI12 images and EISCAT radar observations |
title_short |
Comparison of the open-closed field line boundary location inferred using IMAGE-FUV SI12 images and EISCAT radar observations |
title_full |
Comparison of the open-closed field line boundary location inferred using IMAGE-FUV SI12 images and EISCAT radar observations |
title_fullStr |
Comparison of the open-closed field line boundary location inferred using IMAGE-FUV SI12 images and EISCAT radar observations |
title_full_unstemmed |
Comparison of the open-closed field line boundary location inferred using IMAGE-FUV SI12 images and EISCAT radar observations |
title_sort |
comparison of the open-closed field line boundary location inferred using image-fuv si12 images and eiscat radar observations |
publisher |
Copernicus Publications |
publishDate |
2010 |
url |
https://doi.org/10.5194/angeo-28-883-2010 https://doaj.org/article/4edd7a8754354a4ab504f76b31dd351e |
genre |
EISCAT |
genre_facet |
EISCAT |
op_source |
Annales Geophysicae, Vol 28, Pp 883-892 (2010) |
op_relation |
https://www.ann-geophys.net/28/883/2010/angeo-28-883-2010.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-28-883-2010 0992-7689 1432-0576 https://doaj.org/article/4edd7a8754354a4ab504f76b31dd351e |
op_doi |
https://doi.org/10.5194/angeo-28-883-2010 |
container_title |
Annales Geophysicae |
container_volume |
28 |
container_issue |
4 |
container_start_page |
883 |
op_container_end_page |
892 |
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1766400015404630016 |