A new method of measuring snowflake size and falling velocity
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- SUZUKI Michiya
- Faculty of Engineering, Yamagata University
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- SHA Kokusho
- Faculty of Engineering, Yamagata University
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- EBIHARA Hideaki
- Faculty of Engineering, Yamagata University
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- AKIBA Toshihiro
- Faculty of Engineering, Yamagata University
Bibliographic Information
- Other Title
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- 降雪粒子の大きさと落下速度の新観測法
- コウセツ リュウシ ノ オオキサ ト ラッカ ソクド ノ シン カンソクホウ
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Abstract
Customarily, the falling velocity of a particular snowflake is measured directly from the time interval taken for it to fall through a given vertical distance, and the size of the snowflakes is examined on dyed filter paper separately. That is, the direct and simultaneous measurements of the size and falling velocity of aggregate snowflakes in the falling space cannot be performed outdoors.<BR>In order to measure both at once, the following new technique has been developed. The moving snowflakes are photographed by two cameras (one camera measures the falling velocity, the other the size) against a dark background. The shutter speeds of the two cameras are set at 1/30 and 1/1000 second. Since both of them are operated simultaneously, two pictures for the same snowflakes are obtained. From the short streak in the picture with a slow shutter speed, the velocity is measured. From the camera with a faster shutter speed, the size and number of the snowflakes are obtained. These negative films are magnified by a factor of 1.5 by a slide projector. Thus, the size, falling velocity and mean concentration of falling snowflakes are measured simultaneously from each negative. This paper describes the effectiveness of this new method as demonstrated by outdoor experiments, and shows that the falling velocity depends upon the size and the concentration of snowflakes under calm conditions.
Journal
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- Journal of the Japanese Society of Snow and Ice
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Journal of the Japanese Society of Snow and Ice 43 (1), 1-8, 1981
The Japanese Society of Snow and Ice
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Details 詳細情報について
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- CRID
- 1390001206461378944
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- NII Article ID
- 130000907768
- 10005318663
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- NII Book ID
- AN00131221
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- ISSN
- 18836267
- 03731006
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- NDL BIB ID
- 2307469
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- Text Lang
- ja
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- Data Source
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- JaLC
- NDL
- Crossref
- CiNii Articles
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- Abstract License Flag
- Disallowed