A thermodynamic mechanism for the maintenance of the moist-tropical margins
| Project/Area Number |
19H01966
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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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| Review Section |
Basic Section 17020:Atmospheric and hydrospheric sciences-related
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| Research Institution | Nagoya University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
鈴木 健太郎 東京大学, 大気海洋研究所, 教授 (00396946)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥17,030,000 (Direct Cost: ¥13,100,000、Indirect Cost: ¥3,930,000)
Fiscal Year 2021: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2020: ¥6,110,000 (Direct Cost: ¥4,700,000、Indirect Cost: ¥1,410,000)
Fiscal Year 2019: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000)
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| Keywords | 熱帯気象 / 衛星観測 / 熱帯気象学 / 衛星地球観測 / 数値モデル評価 |
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| Outline of Research at the Start |
スコールに代表される多雨地域の熱帯に比べ、グアムやハワイが位置する亜熱帯は比較的穏やかな気候に恵まれる。その背後には熱帯と亜熱帯をつなぐ壮大な大気循環（ハドレー循環）が知られる。本研究課題では、従来考えられてきたような地理的に固定された循環場の描像に代わり、日々の気象場に応じ動的にゆらぐ熱帯と亜熱帯の境界の動態に着目し、衛星観測や数値シミュレーション解析を通じてそのメカニズム理解に迫る。
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| Outline of Final Research Achievements |
A moist large-scale ascent with active cumulus clouds prevails near the equator, while dry subsidence suppresses convective activity in the latitudes where the upper-tropospheric flow turns downward. This well-known picture of the Hadley circulation explains, from the perspectives of atmospheric dynamics, the unique low-latitude climate of the wet and rainy tropics and the dry and sunny subtropics in a consistent manner. On the other hand, the dynamics of the "margin" separating the tropics and subtropics has been a focus of recent research. In this study, we conducted an energy budget analysis using satellite observation data and reanalysis data, offering a physical explanation for the mechanism of the margin between the tropics and subtropics dominated by the variability in water vapor and convective activity. At the same time, related phenomena such as convective self-aggregation and tropical convergence zones were studied.
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| Academic Significance and Societal Importance of the Research Achievements |
熱帯における気象の成り立ちは地球水循環・エネルギー循環の要をなし、その動態を深く理解することは地球温暖化を含む気候変化やエルニーニョ現象などの年々変動の理解にも関連する幅広い影響力がある。本研究課題の成果は、気候モデルや気象予報数値モデルなどの性能評価に有用な観測的知見を与えるものであり、中長期的に気候予測・気象予報の精度向上に資するデータの礎を築く意味で重要である。
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Report
(4 results)
Research Products
(12 results)
