| Project/Area Number |
11205203
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| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
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| Allocation Type | Single-year Grants |
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| Review Section |
Science and Engineering
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| Research Institution | Kagoshima University |
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Principal Investigator |
ICHIKAWA Hiroshi Kagoshima Univ., Fac. Fisheries, Professor, 水産学部, 教授 (60128410)
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| Co-Investigator(Kenkyū-buntansha) |
MAEDA Hiroto Kagoshima Univ., Fac. Fisheries, Assoc. Prof., 水産学部, 助教授 (80238873)
ICHIKAWA Toshihiro Kagoshima Univ., Fac. Science, Prof., 理学部, 教授 (30109110)
MATSUNO Takeshi Kyushu Univ., Res. Inst. Appl. Mech., Prof., 応用力学研究所, 教授 (10209588)
NAKAMURA Hirohiko Kagoshima Univ., Fac. Fisheries, Lecturer, 水産学部, 講師 (50284914)
SAKURAI Masahito Kagoshima Univ., Fac. Engineer., Assoc. Prof., 工学部, 助教授 (10094145)
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| Project Period (FY) |
1999 – 2002
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| Keywords | East China Sea / Continental Shelf / Kuroshio / Nutrients / Oceanic condition / Monitoring / Water Mass / Chlorophyll |
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| Research Abstract |
The objectives of our research program are to estimate the shot-periods and small-scale variation components in the oceanographic data obtained during about one-month long cruise in wide survey area, and to elucidate the current system and distribution mechanism of water mass by using the biogeoche-mical tracers. The major results are as follows.
1. Short-periods and small-spatial scale variations (1)By the 17 cyclic surveys for 55 hours running around 3 points ca 15 km apart over the continental shelf of 110 m depth, we have obtained the tidal period variations of 3-D distributions of water properties including biogeochemical tracers (nutrients etc.). (2)By the surveys repeated several times during about 10 days along short lines crossing the Kuroshio front near the continental shelf break, we have found the time scale of low salinity water subduction into the middle layer of Kuroshio Water to be only a few days. (3)By the surveys 5 to 10 days apart at same stations in the Kuroshio or continental shelf region, we have found the large variation of water properties to be accompanied with the variation of Kuroshio.
2.Discrimination and tracking of water masses (1)By the four wide area surveys with fine station spacing over the continental shelf and the Kuroshio regions, we have obtained the detailed 3-D distributions of water properties and currents. (2)We have found the non-conservative materials such as particulate organic matter (carbon and nitrogen), chlorophyll, nutrients, and oxygen, and each amount of three communities of picoplankton discriminated by fluocytometer to be utilized in the discrimination of water masses and tracking their movements as the indicators. (3)We have found that the water mass of which salinity and dissolved oxygen are slightly lower than the Kuroshio Water, occupies the rather wide area over the outer continental shelf.
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