| Project/Area Number |
01460059
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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 |
Space and upper atmospheric physics
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| Research Institution | Tohoku University |
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Principal Investigator |
FUKUNISHI Hiroshi Tohoku University, Faculty of Science, Professor, 理学部, 教授 (90099937)
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| Co-Investigator(Kenkyū-buntansha) |
OKANO Shoichi Tohoku University, Faculty of Science, Associate Professor, 理学部, 助教授 (10004483)
MORIOKA Akira Tohoku University, Faculty of Science, Associate Professor, 理学部, 助教授 (50004479)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥6,000,000 (Direct Cost: ¥6,000,000)
Fiscal Year 1990: ¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 1989: ¥3,300,000 (Direct Cost: ¥3,300,000)
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| Keywords | Ozone / Heterodyne Spectroscopy / Stratosphere / Tunable Diode Laser / Infrared Spectroscopy / Atmospheric Minor Constituents / Inversion Method / 波長可変半導体レ-ザ- / 硝酸 |
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| Research Abstract |
1. Improvement of laser heterodyne spectrometer and validity of observation results
(1) Signal-to-noise ratio of the laser heterodyne spectrometer with a tunable diode laser as a local oscillator has been improved to a level of greater than 1000 for an observation time of less than 1 hour. This made it possible to reduce the lower limit of the altitude range for ozone observation from 10km in the past to 7km.
(2) Concurrent observations of the altitude profile of ozone with the laser heterodyne spectrometer and an ozonesonde have been performed for 4 times. Validity of the laser heterodyne measurements was confirmed from the good agreement in the results obtained by the two methods.
(3) Long-term comparison in total ozone amounts obtained from laser heterodyne measurements and those from Dobson spectrophotometer measurements made at Sapporo and Tateno showed validity of the laser heterodyne results.
2. Observation results for ozone
Ozone observations were performed for 79 days in 1989 fiscal year and 68 days in 1990 fiscal year. Seasonal variations in total ozone which have a maximum in spring and minimun in autum, and large day-to-day variation in early spring were obtained. Increase of ozone mixing ratio has been sometimes observed around tropopause altitude. Comparison between the observed profiles of ozone mixing ratio and potential vorticities calculated from meteorological sonde data showed that the correlation between the two values is as high as 0.944, and that the increase of ozone around the tropopause is caused by flowing ozone rich stratospheric air into the tropospnere associated with tropopause folding.
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