昭和基地における強風時の光を利用した飛雪観測(予報)
The present study describes the optical technique that has been developed to measure the variation of the spatial density of blowing snow particles suspended in air. The light source (the emitter) used was an incandescent lamp (12V, 20 W), and a diameter of light beam was 46mm. The receiver was used...
| Main Authors: | , , , |
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| Format: | Report |
| Language: | Japanese |
| Published: |
研究論文
1975
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| Subjects: | |
| Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=7813 http://id.nii.ac.jp/1291/00007813/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=7813&item_no=1&attribute_id=18&file_no=1 |
| Summary: | The present study describes the optical technique that has been developed to measure the variation of the spatial density of blowing snow particles suspended in air. The light source (the emitter) used was an incandescent lamp (12V, 20 W), and a diameter of light beam was 46mm. The receiver was used a photo transister. This instruments were set in two levels of 1 m and 2m at Syowa Station (69° S, 39.5°E) in 1973. The transmission path of light were 4.5m in both case. If it is assumed that snow particles in blowing snow are the same size and the same shape, then the attenuation of a light beam should depend on the spatial density of blowing snow. The emprical correlations between the attenuation of a light beam (the transmittivity) and the mean visibility, and between the transmittivity and the drift flux were given for practical use. Observations made only in night time and during the period of high winds (also called Antarctic blizzards). For example, when the mean wind speed at 10m level was 30 m/s, the drift flux at 1 m level changed quickly between 80 and 400g/m^2・s. |
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