Clarification of process and mechanism for inversion of thermal stratification observed in closed saline ponds
| Project/Area Number |
16K18772
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Rural environmental engineering/Planning
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| Research Institution | Kyushu University |
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Principal Investigator |
Ozaki Akinori 九州大学, 熱帯農学研究センター, 助教 (40535944)
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| Research Collaborator |
Kaewjantawee Panitan
Anongponyoskul Monton
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2018: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2017: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2016: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
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| Keywords | 二重拡散対流 / 熱塩対流 / 密度成層 / 塩分成層 / 水温成層 / 水産養殖池 / 現地観測 / 水理実験 / 降雨発生装置 / 密度成層流 / PIV / 密度成層水域 / 二重対流拡散 |
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| Outline of Final Research Achievements |
In closed saline ponds, intermittent rainfall during the rainy season can cause salinity stratification, and strong solar radiation can cause thermal stratification. The combination of these factors may result in thermohaline convection in the ponds. Thermohaline convection in a closed saline pond can in turn induce the inversion of thermal stratification in these ponds. We conducted field observations and test tank experiments to determine how the inversion of thermal stratification in closed saline ponds was influenced by the variation in the weather and water properties. If the pond stratifies into three layers with a salinity gradient in the middle layer, heat storage can occur. The salinity gradient prevents heat from escaping from the lower layer by effectively insulating it from nighttime radiative cooling.
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| Academic Significance and Societal Importance of the Research Achievements |
本研究で取り扱った塩分を閉鎖性水域については，塩水養殖池や閉鎖性が強い内湾等の水産養殖現場も含むが，これらの水域においても水域成層条件および熱条件が揃うことにより，水温逆転現象が発生する可能性がある．近年，世界人口に対する食料供給の観点から水産養殖の需要が高まっているが，水産養殖現場では，養殖物の突発的な死病が発生しており，その原因が特定できていないことが多い．本研究で取り扱った水温逆転現象による高水温状態は，これらの未解明な養殖物死病との関連も示唆されることから，本研究による成果は，物理現象の解明のみならず，水産養殖物の生産性問題に寄与できる点で，社会的意義が高い研究成果である．
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Report
(4 results)
Research Products
(12 results)
