2016 Fiscal Year Final Research Report
Climatology on the lightning with high energy around Japan
| Project/Area Number |
26400463
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Meteorology/Physical oceanography/Hydrology
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| Research Institution | Gunma University |
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Principal Investigator |
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Keywords | 雷 / 落雷エネルギー / WWLLN / 正極雷 / 気候学 |
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| Outline of Final Research Achievements |
Climatological features of lightning, based on stroke energy, were studied. The ratio of strong lightning (>90th percentile of stroke energy) to overall lightning is defined as S-ratio. It is found that a large S-ratio was observed in the grid where lightning activity was very weak. Four regions were found in which the S-ratio exceeded 30% over the ocean in the sub-polar climatic zones of the Northern and Southern Hemispheres. In cold seasons of the two Hemispheres, both the lightning activity and the S-ratio increased. In addition, Siberia also exhibited a large S-ratio (>30%), and both the lightning activity and the S-ratio increased in summer season.
S-ratio exceed 30% over the Kanto district in spring. Most of strong lightning were corresponding to positive lightning. Since it is well known that positive lightning have a larger stroke energy, it is considered that the cumulonimbi that brought strong spring lightning was equivalent to cumulonimbi that brought positive lightning.
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| Free Research Field |
気象学
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