| Project/Area Number |
15KK0157
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| Research Category |
Fund for the Promotion of Joint International Research (Fostering Joint International Research)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Meteorology/Physical oceanography/Hydrology
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| Research Institution | Nagoya University |
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Principal Investigator |
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| Research Collaborator |
Bony Sandrine フランス気象力学研究所(LMD), 主任研究員
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| Project Period (FY) |
2016 – 2018
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥13,390,000 (Direct Cost: ¥10,300,000、Indirect Cost: ¥3,090,000)
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| Keywords | 熱帯気象学 / 衛星地球観測 / 熱帯湿潤対流 / 放射対流相互作用 / 衛星観測 / 衛星リモートセンシング / 気象学・気候学 / 熱帯大気力学 |
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| Outline of Final Research Achievements |
Radiative-convective interactions, although known to be a critical physical element of the Earth’s atmosphere, are not understood in the context of the development of individual convective systems. This work seeks evidence for convective-radiative interactions in satellite measurements, with focus on the variability over the life cycle of tropical convection. Cirrus cloud cover begins to increase, accompanied by a notable reduction of LW cooling, in moist atmospheres even 1-2 days before deep convection is invigorated. A possible mechanism to support this observational implication is discussed using a simple conceptual model. The model suggests that the preceding cirrus clouds could radiatively promote the moistening with the aid of the congestus-mode (or a vertical mode with a lower-tropospheric updraft) dynamics within a short period of time (about 2 days) as observed.
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| Academic Significance and Societal Importance of the Research Achievements |
熱帯は世界有数の多雨地域であるが、熱帯降水雲の発生発達メカニズムには未解明の点も多い。本研究は、熱帯における雨雲強化メカニズムのひとつとして、巻雲がもたらす温室効果が大気下層の湿潤化を促し激しい降水に至る可能性を衛星データ解析と簡単な理論的考察から示した。雲の温室効果と雲対流の相互作用は以前から研究されていたが、上記のプロセスが1-2日程度の短い時間で進行することを指摘した研究は他に類を見ず、新規性の高い発見である。地球温暖化予測などに使われる気候モデルでこのような短時間の放射・対流相互作用が再現されるのか、ひいては将来気候予測の信頼性にどの程度影響がを及ぼすのか、今後の解明が待たれる。
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