| Project/Area Number |
60540254
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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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 | HOKKAIDO UNIVERSITY |
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Principal Investigator |
ENDOH Tatsuo INSTITUTE OF LOW TEMPERATURE SCIENCE, HOKKAIDO UNIVERSITY , Associate Prof., 低温科学研究所, 助教授 (20001844)
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| Co-Investigator(Kenkyū-buntansha) |
TANIGUCHI Takashi FACULTY OF SCIENCE, HOKKAIDO UNIVERSITY, Instructor, 理学部, 助手 (40150247)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 1986: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1985: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | WINTER THUNDERSTORM / POSITIVE DISCHARGE / CHARGE GENERATION MECHANISM / ELECTRICITY SONDE / SNOWFALL CLOUD / レーダ |
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| Research Abstract |
To investigate the atmospheric electric structure of winter thunderclouds,some simultaneous observation were carried out by means of electricity sondes and a radar. The electricity sonde is composed of a part of measuring electric charges on precipitation particles and another part of measuring atmospheric electric potential gradient in the clouds.
In the six cases of the seven cases obtained, electric fields were observed to be positive in the lower part of the clouds or around cloud bases and negative in the upper part of the clouds or near cloud tops.
The sign of electric charge on the precipitation particles were observed to be inverse relation with the sign of electric fields.
In the most typical case, precipitation echoes obtained (RHI) by the radar had a verga shape which meaned that charge separation occured not only vertically but also horisontally. Accordingly, positive space charge in the middle level of the clouds or positive precipitation charges in the upper level of the clouds may be considered to reveal for the ground directly. This is the reason why positive ground discharge occurs predominantly in winter thunderclouds.
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