| Project/Area Number |
17K05658
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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 | Japan, Meteorological Research Institute |
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Principal Investigator |
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| Project Period (FY) |
2017-04-01 – 2024-03-31
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| Project Status |
Completed (Fiscal Year 2023)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2020: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2019: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2018: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2017: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Keywords | データ同化 / 大気状態推定 / 数値天気予報 / 誤差共分散行列 / 観測データ / 誤差相関 / 観測誤差共分散行列 / 気象学 |
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| Outline of Final Research Achievements |
In this study, by improving the accuracy of the error covariance matrix, the most important parameter in data assimilation, we relaxed the restrictions on assimilable observations for global atmospheric state analysis, and made it possible to assimilate a dramatically larger amount of observational information. This resulted in significant improvements in analysis and prediction accuracy and theoretical consistency. We showed that by increasing observational information, high accuracy can be obtained even when the adjoint model of the variational method is replaced by an ensemble forecast. The high-precision background error covariance matrix constructed by objective estimation through ensemble assimilation was analyzed based on network theory, and the basic properties of atmospheric perturbations were clarified.
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| Academic Significance and Societal Importance of the Research Achievements |
大気はカオス系であり、その状態解析や予測の高精度化や理論整合性の向上は重要な科学的知見である。高精度な大気状態解析は、大気科学の発展に不可欠なデータセットの生成を可能にし、これらの発展にも不可欠である。ネットワーク理論による大気摂動の基本構造の解明は大気科学に新しい描像を提供する。また、データ同化を利用する他分野（海洋、固体地球、地球重力圏等）に広範囲に応用可能な普遍的知見となる。大気状態の解析や予測は社会基盤情報であり、その精度や理論整合性の向上は社会的にも重要である。
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