Clarification of global warming based on changes in the deep ocean
| Project/Area Number |
18K03752
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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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| Review Section |
Basic Section 17020:Atmospheric and hydrospheric sciences-related
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| Research Institution | Japan Agency for Marine-Earth Science and Technology |
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Principal Investigator |
Uchida Hiroshi 国立研究開発法人海洋研究開発機構, 地球環境部門(海洋観測研究センター), 主任研究員 (00359150)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2020: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
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| Keywords | 海溝 / 温暖化 / 低塩分化 / 低酸素化 / 深層循環弱化 |
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| Outline of Final Research Achievements |
To clarify evidence of slowing thermohaline circulation based on the observational data, we conducted ship-based temperature, salinity, and dissolved oxygen measurements in super-deep trenches with their surroundings along the pathway of the deep circulation. We successfully measured seawater density in the deep ocean for the first time by using the refractive index density sensor. We also evaluated and corrected the batch-to-batch offsets of the Standard Seawater for salinity measurement and found recent freshening (-0.0006 g/kg/decade) in the deep North Pacific for the first time, which might be related to a reduction of the formation rate of Antarctic Bottom Water.
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| Academic Significance and Societal Importance of the Research Achievements |
地球温暖化により海洋深層でも温暖化が報告されており、数値実験から南極周辺の深層水形成量の減少が北太平洋深層を昇温させるという説がある。深層循環弱化を明らかにするには、深海の微小な変化を検出する必要がある。現状の測定分解能よりも高い測定が期待される、屈折率密度センサーによる深海の海水密度の精密測定に、世界で初めて成功した。また、塩分測定用標準海水の認証値のずれを評価し補正することで、北太平洋深層の２０年間の低塩分化トレンドの検出に初めて成功した。これらの成果は、深海環境変化のモニタリングに道を開くものである。
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Report
(4 results)
Research Products
(12 results)
