2018 Fiscal Year Final Research Report
Understanding of the relationship between typhoon structure and intensity using Doppler radars in the Ryukyu Islands and Philippines
| Project/Area Number |
16H04053
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Meteorology/Physical oceanography/Hydrology
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| Research Institution | University of the Ryukyus |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
和田 章義 気象庁気象研究所, 台風研究部, 主任研究官 (20354475)
久保田 尚之 北海道大学, 理学研究院, 特任准教授 (40359211)
嶋田 宇大 気象庁気象研究所, 台風研究部, 主任研究官 (60750651)
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| Research Collaborator |
IWAI Hironori
ITO Kosuke
YAMAMOTO Masayuki
KITABATAKE Naoko
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | 台風 / 強度 / 気象観測 / ドップラーレーダー |
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| Outline of Final Research Achievements |
The minimum central pressure and flow structure of typhoons were estimated using weather Doppler radars operated in the Ryukyu Islands and the Philippines. Using the results of estimation, a relationship between the structure and intensity of typhoons was investigated. In the 3-year research period, intensity estimation was made for 48 cases of typhoons that passed through the coverage of a radar. Using typhoons undergoing rapid intensification, we clarified that the eyewall contraction (i.e., reduction in radius) is related to the intensity change. We also revealed that a typhoon with a small eye undergoes large intensity changes. In addition, we clarified from observations and numerical simulations that a violent typhoon passing through the Philippines can maintain its strength without suffering ocean cooling if the typhoon can move faster than usual.
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| Free Research Field |
気象学
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| Academic Significance and Societal Importance of the Research Achievements |
気象庁など現業機関が運用するドップラーレーダーを用いて、台風の強度を5分間隔の高頻度で推定することが可能になり、壁雲の軸対称性や半径の変化など、台風の中心近く（半径約100キロ以内）の構造変化が、強度変化と密接に関係することを明らかにした。この手法を用いることで、急速に発達（または衰退）する台風の強度変化を、台風が接近する半日～6時間前から的確に把握することが可能になった。さらに事例を増やし、推定結果の精度が保証されれば、台風防災情報の高度化につなげることができると考えられる。
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