2014 Fiscal Year Final Research Report
A novel dissolved O2 consumption process in mesopelagic waters inferred from observation and model simulation of dissolved oxygen delta18O in open oceanic regions
| Project/Area Number |
24710002
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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 |
Environmental dynamic analysis
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| Research Institution | The University of Tokyo |
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Principal Investigator |
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Keywords | 溶存酸素 / 安定同位体比 / 酸素消費過程 |
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| Outline of Final Research Achievements |
We explored how physical and biological processes affect to the O2 concentrations and d-18O of dissolved O2 relationship in seawater applying a 3-D OGCM to data obtained field observations and laboratory experiment. It failed to reproduce when we adopted the previously reported isotopic fractionation factor (a = 0.98), and prescribed physical parameters. The discrepancy became larger when oxygen saturation level decreased. Sensitivity experiments revealed that (1) the intensity of O2 consumption rate nor physical processes (diffusion/advection) could explain the observed relationship, (2) applying a new kinetic isotope fractionation effect for deep waters rather than commonly used isotope effect could only reproduce the observed relationship. Current result suggests the unidentified deep metabolism process, such as complete O2 consumption by diffusion process predominant process for O2 distribution in the mesopelagic waters rather than that in the epipelagic zone.
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| Free Research Field |
化学海洋
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