What controls the luminosity of polar cap airglow patches?: Implication from airglow measurements in Eureka, Canada in comparison with SuperDARN convection pattern
Polar cap patches are known as islands of enhanced electron density in the polar cap F region ionosphere. To observe the airglow signature of polar cap patches continuously at a fixed point near the center of the MLAT/MLT coordinate system, we started operating an all-sky imager in Eureka, Canada si...
Published in: | Polar Science |
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Format: | Article in Journal/Newspaper |
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ftnipr:oai:nipr.repo.nii.ac.jp:00016471 2023-05-15T16:19:40+02:00 What controls the luminosity of polar cap airglow patches?: Implication from airglow measurements in Eureka, Canada in comparison with SuperDARN convection pattern 2021 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=16471 http://id.nii.ac.jp/1291/00016347/ en eng https://doi.org/10.1016/j.polar.2020.100608 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=16471 http://id.nii.ac.jp/1291/00016347/ Polar Science, 28, 100608(2021) 18739652 Aurora Airglow Imager Polar ionosphere Polar cap patch Journal Article 2021 ftnipr https://doi.org/10.1016/j.polar.2020.100608 2022-12-03T19:43:21Z Polar cap patches are known as islands of enhanced electron density in the polar cap F region ionosphere. To observe the airglow signature of polar cap patches continuously at a fixed point near the center of the MLAT/MLT coordinate system, we started operating an all-sky imager in Eureka, Canada since 2015, where the magnetic latitude is ~87°. By statistically analyzing the 630-nm airglow images from Eureka, it was identified that the luminosity of patches, which is proportional to the electron density in the F region, increases during specific UT interval from 16 to 22 UT. This outstanding UT variation of patch luminosity can be explained simply by the systematic shift of the terminator in the MLAT/MLT coordinate system due to the offset between the geographic and geomagnetic pole. That is, the spatial relationship between the dense source plasma in the sunlit area and the high-latitude convection system controls the UT variation. We also found that when the IMF By is positive, the number of polar cap patches was twice of that in the negative IMF By. By deriving average convection patterns from the archived SuperDARN map potential data, we confirmed that the configuration of plasma convection is more appropriate for patches to be transported toward the magnetic pole during the positive IMF By condition. Article in Journal/Newspaper Geomagnetic Pole Polar Science Polar Science National Institute of Polar Research Repository, Japan Canada Eureka ENVELOPE(-85.940,-85.940,79.990,79.990) Polar Science 28 100608 |
institution |
Open Polar |
collection |
National Institute of Polar Research Repository, Japan |
op_collection_id |
ftnipr |
language |
English |
topic |
Aurora Airglow Imager Polar ionosphere Polar cap patch |
spellingShingle |
Aurora Airglow Imager Polar ionosphere Polar cap patch What controls the luminosity of polar cap airglow patches?: Implication from airglow measurements in Eureka, Canada in comparison with SuperDARN convection pattern |
topic_facet |
Aurora Airglow Imager Polar ionosphere Polar cap patch |
description |
Polar cap patches are known as islands of enhanced electron density in the polar cap F region ionosphere. To observe the airglow signature of polar cap patches continuously at a fixed point near the center of the MLAT/MLT coordinate system, we started operating an all-sky imager in Eureka, Canada since 2015, where the magnetic latitude is ~87°. By statistically analyzing the 630-nm airglow images from Eureka, it was identified that the luminosity of patches, which is proportional to the electron density in the F region, increases during specific UT interval from 16 to 22 UT. This outstanding UT variation of patch luminosity can be explained simply by the systematic shift of the terminator in the MLAT/MLT coordinate system due to the offset between the geographic and geomagnetic pole. That is, the spatial relationship between the dense source plasma in the sunlit area and the high-latitude convection system controls the UT variation. We also found that when the IMF By is positive, the number of polar cap patches was twice of that in the negative IMF By. By deriving average convection patterns from the archived SuperDARN map potential data, we confirmed that the configuration of plasma convection is more appropriate for patches to be transported toward the magnetic pole during the positive IMF By condition. |
format |
Article in Journal/Newspaper |
title |
What controls the luminosity of polar cap airglow patches?: Implication from airglow measurements in Eureka, Canada in comparison with SuperDARN convection pattern |
title_short |
What controls the luminosity of polar cap airglow patches?: Implication from airglow measurements in Eureka, Canada in comparison with SuperDARN convection pattern |
title_full |
What controls the luminosity of polar cap airglow patches?: Implication from airglow measurements in Eureka, Canada in comparison with SuperDARN convection pattern |
title_fullStr |
What controls the luminosity of polar cap airglow patches?: Implication from airglow measurements in Eureka, Canada in comparison with SuperDARN convection pattern |
title_full_unstemmed |
What controls the luminosity of polar cap airglow patches?: Implication from airglow measurements in Eureka, Canada in comparison with SuperDARN convection pattern |
title_sort |
what controls the luminosity of polar cap airglow patches?: implication from airglow measurements in eureka, canada in comparison with superdarn convection pattern |
publishDate |
2021 |
url |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=16471 http://id.nii.ac.jp/1291/00016347/ |
long_lat |
ENVELOPE(-85.940,-85.940,79.990,79.990) |
geographic |
Canada Eureka |
geographic_facet |
Canada Eureka |
genre |
Geomagnetic Pole Polar Science Polar Science |
genre_facet |
Geomagnetic Pole Polar Science Polar Science |
op_relation |
https://doi.org/10.1016/j.polar.2020.100608 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=16471 http://id.nii.ac.jp/1291/00016347/ Polar Science, 28, 100608(2021) 18739652 |
op_doi |
https://doi.org/10.1016/j.polar.2020.100608 |
container_title |
Polar Science |
container_volume |
28 |
container_start_page |
100608 |
_version_ |
1766006073882312704 |