2006 Fiscal Year Final Research Report Summary
The annual variation of sinking particles flux corresponding to material transports of North Pacific Subarctic Gyre
| Project/Area Number |
15310001
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | Hokkaido University |
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Principal Investigator |
YANADA Mitsuru Hokkaido University, Fac. of Fis. Sci., Prof. (00166555)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Kozo Kyushu Univ., Fac. of Sci., Prof. (30244875)
OHISHI Hiroji HOKKAIDO UNIVERSITY, Fac. of Fis. Sci., Lec. (80241371)
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| Project Period (FY) |
2003 – 2006
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| Keywords | Sediment Trap / Annual Variation / Sinking Particles / Alaskan Stream / North Pacific / Bering Sea / Calcium Carbonate / Biogenic Opal |
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| Research Abstract |
The aim of this study is to predict the changes of marine environment in the future by elucidating hydrographic environmental factors, e. g. the Alaskan Stream, which cause the seasonal and annual variations in the processes of primary production in the central subarctic Pacific and the Bering Sea Basin.
The deployment and recovery of time-series sediment trap array were carried out by the T/S "Oshoro Maru" belonging to Hokkaido University every year from 2003 to 2007 in the Bering Sea Basin (AB: 53. 5°N, 177. 0°W) and in the central subarctic Pacific (SA: 49. 0°N, 174. 0°W).
A part of obtained sinking particles was measured for the determinations of total mass, total carbon, organic carbon, total nitrogen, total amino acids, hexosamine, biogenic opal, calcium carbonate and stable isotope. The other parts of the sinking particles were also observed using a microscope for analysis of diatoms, radiolarians, 〓ccoliths and foraminifera. The variation of hydrographic environments was elucidated by calculations of heat, salts and volume transports of the Alaskan Stream and the Subarctic Current using CTD, XCTD and Argo floats data.
As a result, in the Bering Sea Basin a high maximum peak flux of sinking particles with relatively high contribution of diatoms was observed in the spring season of 2003. A time lag of the maximum peak flux of sinking particles composed of coccoliths and foraminifera was also observed in the central subarctic Pacific. These results make us expect some abnormalities on the characteristics of sinking particles during 2003-2007, implying some abnormal sinking processes or production of marine organisms in both AB station and SA station during 2003-2007. These variations for the flux and the characteristics of sinking particles may relate to the variation of surface temperature condition.
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Research Products
(23 results)
