1997 Fiscal Year Final Research Report Summary
The Maritime Continent Thunderstorm Experiment
| Project/Area Number |
08041123
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Field Research |
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| Research Field |
電力工学・電気機器工学
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| Research Institution | Osaka University |
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Principal Investigator |
KAWASAKI Zen-Ichiro Osaka University, Department of Electrical Engineering, Assistant Professor, 工学部, 助教授 (60126852)
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| Co-Investigator(Kenkyū-buntansha) |
MAZUR Vlad National Severe Storms Laboratory, Group Leader, 主任研究員
GUMLEY Richard Global Lightning Technology, Engineering Section, President, 代表
DOWDEN R. オタゴ大学, 工学部, 教授
FUNAKI Tuyoshi Osaka University, Department of Electrical Engineering, Research Associate, 工学部, 助手 (20263220)
WANG Daohong Gifu University, Department of Electrical Engineering, Research Associate, 工学部, 助手 (20273120)
DOWDEN Richard University of Otago, Department of Electrical Engineering, Professor
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| Project Period (FY) |
1996 – 1997
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| Keywords | Maritime Thunderstorm / Inter Tropical Convergence Zone / Positive Lightning / Interferometer / Visualization of Lightning Channel / Velocity of Lightning Stroke / Rocket Triggered Lightning |
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| Research Abstract |
Lightning observations in a region of the inter tropical convergence zone (ITCZ) were carried out durring two thunderstorm seasons. Darwin Australia was chosen for the campaign site because of its frequent occurrence of thunderstorms during the building up stage of its monsoon seasons. The first campaign in Darwin was held from early November through end of November in 1996. The second campaign was conducted from mid November through mid December in 1997. The main item of observations was reconstruction of lightning channels inside thundercloud by means of interferometer observations. Since we equipped two systems of interferometer with the base line length of 15 km, three dimensional imaging of lightning channels was besically available.
To obtain features of the progression of lightning discharges for multiple strokes quantitatively, two dimensional analysis for stepped leader propagation are mainly given for first stepped leader and subsequent leaders. The velocity of leader progressions were obtained for both the first stepped leader and subsequent leaders as a function of time. We also calculated the average velocities, and learned the discrepancy among stepped leaders, dart leaders and dart stepped leader from the aspects of their propagation. Wc leaned the discrepancy of the characteristic difference between classic multiple strokes and multi-point strokes. According to the observations in Darwin we can conclude that the location of the initiation of discharges inside clouds for both classic multiple strokes and multi point strokes are basically same.
Many Red Sprites which are the discharges from the cloud top to the lower ionosphere were recorded, and this was the additional observations.
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