1995 Fiscal Year Final Research Report Summary
Optical study on the thermo-ionospheric equatorial anomaly
| Project/Area Number |
05041055
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Field Research |
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| Research Institution | University of Tokyo |
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Principal Investigator |
OGAWA Toshihiro Graduate School of Science, University of Tokyo Prof., 大学院・理学系研究科, 教授 (70011616)
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| Co-Investigator(Kenkyū-buntansha) |
KIYAMA Yoshitaka Faculty of Science, Niigata University Assistant, 理学部, 助手 (50018272)
TAGUCHI Makoto Faculty of Science, Tohoku University Assistant, 理学部, 助手 (70236404)
OKANO Shoichi National Institute of Polar Research Prof., 教授 (10004483)
FUKUNISHI Hiroshi Faculty of Science, Tohoku University Prof., 理学部, 教授 (90099937)
KITA Kazuyuki Graduate School of Science, University of Tokyo Assistant, 大学院・理学系研究科, 助手 (30221914)
IWAGAMI Naomoto Graduate School of Science, University of Tokyo Associate Prof., 大学院・理学系研究科, 助教授 (30143374)
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| Project Period (FY) |
1993 – 1995
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| Keywords | equatorial anomaly / airglow / ionospheric F region / thermosphere |
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| Research Abstract |
To implement one of the research projects on "Energy and Dynamics of Coupled Ionosphere-Thermosphere System" of Japanese Solar-Terrestrial Energy Program (STEP), we focused on the dynamics of the fine structures of ionospheric F-region plasma in the equatorial anomaly which appears as anomalously high electron densities in the zones of geomagnetic latitudes (]SY.+-.])15ﾟ. We were able to observe the fine structures of F-region electron density distribution and thermospheric temperature and wind system using an optical sensing technique to measure the all-sky distribution of the intensity, line width and line shift of the atomic oxygen 630m airglow that is excited through the recombination of molecular ions and electrons. The observations were made at the top of Mt. Haleakala, Maui Is., Hawaii located at the north zone of the equatorial anomaly, and Watukosek in East Java of Indonesia located in the south zone of the equatorial anomaly.
We stayd at the observatory on the top of Mt. Halea
… More
kala in February 1993 and November 1993,1994 and 1995 to measure the all-sky intensity distributions of the atomic oxygen 630nm and 557.7nm, Na 589.3nm and OH band airglows using an all-sky rapid-scanning photometer and a monochromatic all-sky imager, and to measure the line width and shift of the 630nm airglow. These measurements provided us with all-sky structures of electron density in the F-region, neutral species in the lower thermosphere, and thermospheric temperature and wind system. We found that the horizontal distribution in the F-region electron density varied independently on those structures in the lower themosphere during a magnetic storm, suggesting that a wave disturbance responsible for the electron density variation does not come from the lower atmosphere.
We set up a meridional scanning photometer at Watukosek and asked a technician at LAPAN Watukosek Observatory to measure the 630nm and OH airglows. We visited Watukosek several times during this project to repair the photometer. A north-south oriented stripe structure of the 630nm airglow was observed from time to time. This structure which is one of the typical manifestations of the F-region plasma is found to be not correlated with that of the OH airglow, suggesting that the lower atmosphere is not responsible for generating this stripe structure. Less
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Research Products
(2 results)
