First tomographic observations of the Midlatitude Summer Nighttime Anomaly over Japan
Recently, a chain of digital beacon receivers has been established over Japan, mainly for the tomographic imaging of the ionosphere. These receivers are installed at Shionomisaki (33.45 degrees N, 135.8 degrees E), Shigaraki (34.85 degrees N, 136.1 degrees E), and Fukui (36.06 degrees N, 136 degrees...
Published in: | Journal of Geophysical Research: Space Physics |
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American Geophysical Union �(AGU)
2009
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Online Access: | https://doi.org/10.1029/2009JA014439 http://ir.lib.ncku.edu.tw/handle/987654321/98280 |
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ftchengkunguniv:oai:ir.lib.ncku.edu.tw:987654321/98280 2023-05-15T18:43:19+02:00 First tomographic observations of the Midlatitude Summer Nighttime Anomaly over Japan Thampi, Smitha V. Lin, Charles Liu, Huixin Yamamoto, Mamoru Plasma and Space Science Center 2009-10-31 https://doi.org/10.1029/2009JA014439 http://ir.lib.ncku.edu.tw/handle/987654321/98280 Eng en_US eng American Geophysical Union �(AGU) Journal of Geophysical Research-Space Physics, Vol. 114, pp. A10318 2009 ftchengkunguniv https://doi.org/10.1029/2009JA014439 2016-05-22T07:10:04Z Recently, a chain of digital beacon receivers has been established over Japan, mainly for the tomographic imaging of the ionosphere. These receivers are installed at Shionomisaki (33.45 degrees N, 135.8 degrees E), Shigaraki (34.85 degrees N, 136.1 degrees E), and Fukui (36.06 degrees N, 136 degrees E), which continuously track the Low Earth Orbiting Satellites (LEOS), and the simultaneous line-of-sight Total Electron Content (TEC) data are used for tomographic reconstruction. In the images obtained during July 2008, it is seen that the nighttime electron densities exceed the daytime values on almost all days over latitudes > 33-34 degrees N. On several days, these northern latitudes show enhanced electron densities compared to the low-latitude region during nighttime. These are the prominent features of the "Midlatitude Summer Nighttime Anomaly (MSNA)'' that is recently observed in the northern hemisphere and is considered similar to the nighttime Weddell Sea Anomaly (WSA). This is the first study of the MSNA using tomographic technique and found its significant day-to-day variability. The ionosonde data from Wakkanai (45.4 degrees N, 141.7 degrees E), ground-based GPS TEC observations using the GEONET, CHAMP in situ electron density measurements, and Formosat3/COSMIC (F3/C) occultation measurements are also used to confirm the presence of MSNA over this region and to examine its variability. It is seen that, in general, during the local summer period, electron density over the northern latitudes is highest at similar to 2000-2100 LT and the latitudinal enhancement in electron density also begins to appear around the same time, which continues to exist even at later hours. Other/Unknown Material Weddell Sea National Cheng Kung University: NCKU Institutional Repository Weddell Weddell Sea Journal of Geophysical Research: Space Physics 114 A10 n/a n/a |
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Open Polar |
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National Cheng Kung University: NCKU Institutional Repository |
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ftchengkunguniv |
language |
English |
description |
Recently, a chain of digital beacon receivers has been established over Japan, mainly for the tomographic imaging of the ionosphere. These receivers are installed at Shionomisaki (33.45 degrees N, 135.8 degrees E), Shigaraki (34.85 degrees N, 136.1 degrees E), and Fukui (36.06 degrees N, 136 degrees E), which continuously track the Low Earth Orbiting Satellites (LEOS), and the simultaneous line-of-sight Total Electron Content (TEC) data are used for tomographic reconstruction. In the images obtained during July 2008, it is seen that the nighttime electron densities exceed the daytime values on almost all days over latitudes > 33-34 degrees N. On several days, these northern latitudes show enhanced electron densities compared to the low-latitude region during nighttime. These are the prominent features of the "Midlatitude Summer Nighttime Anomaly (MSNA)'' that is recently observed in the northern hemisphere and is considered similar to the nighttime Weddell Sea Anomaly (WSA). This is the first study of the MSNA using tomographic technique and found its significant day-to-day variability. The ionosonde data from Wakkanai (45.4 degrees N, 141.7 degrees E), ground-based GPS TEC observations using the GEONET, CHAMP in situ electron density measurements, and Formosat3/COSMIC (F3/C) occultation measurements are also used to confirm the presence of MSNA over this region and to examine its variability. It is seen that, in general, during the local summer period, electron density over the northern latitudes is highest at similar to 2000-2100 LT and the latitudinal enhancement in electron density also begins to appear around the same time, which continues to exist even at later hours. |
author2 |
Plasma and Space Science Center |
author |
Thampi, Smitha V. Lin, Charles Liu, Huixin Yamamoto, Mamoru |
spellingShingle |
Thampi, Smitha V. Lin, Charles Liu, Huixin Yamamoto, Mamoru First tomographic observations of the Midlatitude Summer Nighttime Anomaly over Japan |
author_facet |
Thampi, Smitha V. Lin, Charles Liu, Huixin Yamamoto, Mamoru |
author_sort |
Thampi, Smitha V. |
title |
First tomographic observations of the Midlatitude Summer Nighttime Anomaly over Japan |
title_short |
First tomographic observations of the Midlatitude Summer Nighttime Anomaly over Japan |
title_full |
First tomographic observations of the Midlatitude Summer Nighttime Anomaly over Japan |
title_fullStr |
First tomographic observations of the Midlatitude Summer Nighttime Anomaly over Japan |
title_full_unstemmed |
First tomographic observations of the Midlatitude Summer Nighttime Anomaly over Japan |
title_sort |
first tomographic observations of the midlatitude summer nighttime anomaly over japan |
publisher |
American Geophysical Union �(AGU) |
publishDate |
2009 |
url |
https://doi.org/10.1029/2009JA014439 http://ir.lib.ncku.edu.tw/handle/987654321/98280 |
geographic |
Weddell Weddell Sea |
geographic_facet |
Weddell Weddell Sea |
genre |
Weddell Sea |
genre_facet |
Weddell Sea |
op_relation |
Journal of Geophysical Research-Space Physics, Vol. 114, pp. A10318 |
op_doi |
https://doi.org/10.1029/2009JA014439 |
container_title |
Journal of Geophysical Research: Space Physics |
container_volume |
114 |
container_issue |
A10 |
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n/a |
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n/a |
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1766233641648652288 |