2018 Fiscal Year Final Research Report
Development of high-precision prediction method of heavy rainfall with dual polarization radar
| Project/Area Number |
15K01273
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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 |
Natural disaster / Disaster prevention science
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| Research Institution | Japan, Meteorological Research Institute |
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Principal Investigator |
ADACHI Ahoro 気象庁気象研究所, 気象衛星・観測システム研究部, 主任研究官 (80354520)
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| Co-Investigator(Kenkyū-buntansha) |
石元 裕史 気象庁気象研究所, 気象衛星・観測システム研究部, 室長 (70281136)
南雲 信宏 気象庁気象研究所, 気象衛星・観測システム研究部, 研究官 (30624960)
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| Research Collaborator |
Yamauchi Hiroshi
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| Project Period (FY) |
2015-04-01 – 2019-03-31
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| Keywords | 二重偏波レーダー / 降水の粒径分布推定 / 降水強度推定 |
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| Outline of Final Research Achievements |
Since prediction of local heavy rainfalls, which occur frequently in recent years is difficult even for advanced numerical models, it is important to observe heavy rain with weather radar in advance. However, the rainfall estimated from the conventional radar may have an error of up to 100% in some conditions. Therefore, many countries have been introducing dual polarization radar to achieve high accuracy in recent years. Specifically, empirical formulas are applied to the polarization parameters observed by polarimetric radar to estimate rainfall. However, strictly speaking, the empirical formula needs to be modified according to the temperature, type of precipitation, time, and location, which is virtually impossible. Thus, in this study, we succeeded in developing a method that has been considered difficult, in which the rainfall is theoretically estimated only from the observed polarimetric parameters without using any empirical formulas for the first time in the world.
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| Free Research Field |
レーダー気象学
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| Academic Significance and Societal Importance of the Research Achievements |
「局地的豪雨」による被害を減らすには積雲が発達する前にレーダーで捉える必要がある。しかし従来の気象レーダーによる降水強度の推定精度は必ずしも十分ではない（最大誤差100％程度）。近年米国（2013-）や日本（2016-）を始め世界各国で気象用二重偏波レーダーが導入されつつあり、観測される偏波パラメータから経験式を用いて降水強度を従来より高い精度(誤差30%程度)で推定している。しかし厳密にはこの経験式は場所や時間などにより変更する必要がある。そこで本研究では経験式を用いずに、観測された偏波パラメータだけから理論的に降水強度を推定するという、従来は困難とされていた手法を世界で初めて開発した。
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