| Project/Area Number |
63460043
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
気象・海洋・陸水学
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| Research Institution | University of Tokyo |
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Principal Investigator |
OGAWA Toshihiro University of Tokyo, Faculty of Science, Professor, 理学部, 教授 (70011616)
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| Co-Investigator(Kenkyū-buntansha) |
SHIBASAKI Kazuo Kokugakuin University, Faculty of Literature, Associate Professor, 文学部, 助教授 (00178899)
IWAGAMI Naomoto University of Tokyo, Faculty of Science, Associate Professor, 理学部, 助教授 (30143374)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 1989: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1988: ¥3,200,000 (Direct Cost: ¥3,200,000)
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| Keywords | Stratospheric Ozone / Nitrogen Dioxide / Nitrogen Trioxide / Balloon Observation |
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| Research Abstract |
The final goal of this research is to validate the stratospheric photochemical model by comparing model calculations with a simultaneous data set of stratospheric altitude profiles of nitrogen dioxide, nitrogen trioxide and ozone. Star occultation experiment aboard a stratospheric balloon will enable us to observe nocturnal variations in the altitude profiles of these species. Development of a balloon-borne instrument useful for the nighttime star occultation experiment is crucial for this research. Under the financial support of this gran-in-aids, the balloon-borne instrument was to be designed, fabricated and tested.
Visible absorption spectroscopy in the nighttime condition is the only technique capable of a simultaneous measurement of nitrogen dioxide, nitrogen trioxide and ozone. Altitude profiles of these species will be observed every 1-2 hours with the star occultation method by using the setting stars of magnitude less than -1. The balloon-borne instrument for this particular o
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bservation constitutes of a star seeker/tracker, a telescope and photometric units. A star seeker/tracker scans the sky near the western horizon to seek a star brighter than -l magnitude, and after finding the object star, the telescope locks it on to be kept following it by means of a servo system consisting of a star sensor and driving motors. The telescope has a main mirror of 20 cm diameter. A grating spectrometer is not applicable for this instrument because of a faint light source of a star. Therefore, a photome tric method with an optical filter is employed. Extraction of the absorption due to those gases is possible in terms of differential absorption at two wavelength bands; one is located at the center of the absorption band of the gas and the other is located at adjacent wavelengths. 6 wavelength bands should be chosen for the 3 gaseous species. Because of the nighttime stratospheric operation, the balloon-borne instrument should be designed so as to be adapted to a vacuum condition and to be kept warm.
The star/tracker and the telescope have been fabricated and tested. Fabrication of the photometric units will be completed soon. The whole instrument will be integrated and tested in the laboratory and in the ground field. Preparation for a balloon flight will be finalized by making a balloon gondola. Less
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