Language：Japanese   Publisher：Acta Oceanologica Sinica  

DOI： 10.1007/s13131-020-1603-3

Scopus

Language：Japanese   Publisher：Journal of Marine Science and Engineering  

DOI： 10.3390/JMSE8060402

Scopus

Language：Japanese   Publisher：Biogeosciences  

DOI： 10.5194/bg-17-2441-2020

Scopus

Language：Japanese   Publisher：Scientific Reports  

DOI： 10.1038/s41598-019-46364-9

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PubMed

Language：Japanese   Publisher：Journal of Geophysical Research: Oceans  

DOI： 10.1029/2018JC014771

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Language：Japanese   Publisher：Geophysical Research Letters  

DOI： 10.1029/2019GL082680

Scopus

Language：Japanese   Publisher：Coastal Oceanography Research Committee, the Oceanographic Society of Japan  

Plankton community structure, standing stocks and productivity were compared between upstream and downstream of theTokara Strait based on Lagrangian oceanographic observations and sampling along the Kuroshio. Surface waters above 200mwere represented by lower temperature and salinity, and nutrients and chlorophyll a concentrations at the subsurface were higherdownstream than upstream. No significant difference was found in the zooplankton community structure, and the predominantcomponents were naked ciliates for microzooplankton and copepods for net zooplankton. Although the protein synthetase activityof the net zooplankton community was high throughout the stations, large metazoans were one cause of the increased biomass andproduction rates downstream. These results suggest that the nutrient supply and phytoplankton increased at the subsurface, andthe net zooplankton biomass and productivity increased downstream of the Tokara Strait.

DOI： 10.32142/engankaiyo.2019.8.009

Language：Japanese   Publisher：The Japanese Society of Fisheries Oceanography  

<p>This study investigated transport processes of red tilefish <i>Branchiostegus japonicus</i> from the East China Sea to the coastal area of Miyazaki Prefecture by particle-tracking experiments. Particles were released from areas along the shelf break of the East China Sea in autumn, which are the main spawning ground and season, respectively, and the movement patterns and paths were examined using reanalysis data of an ocean data assimilation system. After 45 days from the release, which is the average duration until settlement, 0.01–0.7% of particles released in the East China Sea reached the coastal area of Miyazaki Prefecture. Among them, 90% and 10% of particles passed through the Ohsumi and the Tokara Straits, respectively. The number of particles reaching Miyazaki Prefecture was positively correlated with those passing through the Ohsumi Strait, while mass arrival events were further related to the deceleration of the Ohsumi Branch Current caused by a small meander of the Kuroshio. Proportions of particles by destination at Day 45, including those not reaching Miyazaki Prefecture, were 10.8% to the Pacific, 1.5% to the Sea of Japan, and 88% remained within the East China Sea. Therefore, it is likely that red tilefish has a major reproduction cycle within the East China Sea, while larvae and juveniles were also supplied from there to Japanese coastal areas. Finally, it is suggested that the Ohsumi Strait is the main passage of larval/juvenile transport of red tilefish, from the East China Sea to the coastal areas of Miyazaki prefecture.</p>

DOI： 10.34423/jsfo.83.2_93

Language：Japanese   Publisher：Coastal Oceanography Research Committee, the Oceanographic Society of Japan  

Under the Grants-in-Aid for Scientific Research in Innovative Areas（MEXT）project "Ocean Mixing Study（OMIX）", weestablished a system to measure the turbulent nitrate flux by attaching a small nitrate sensor on a turbulence profiler. In thispaper, we explain the instrument setup, the data processing method considering measurement errors, and then demonstrate thecapability of the developed observational system.

DOI： 10.32142/engankaiyo.2019.8.008

Language：Japanese   Publisher：Japan Society of Civil Engineers  

&nbsp;We have measured a time series of current velocity off Cape Shiono-misaki from April 20, 2016 to April 20, 2017 with a moored ADCP in order to investigate the characteristics of variation of the Kuroshio current in relation to ocean current power generator. The Kuroshio has taken a non-large-meander path for the measurement period. It is clarified from the measurement results that the currents at a depth of about 50m are characterized by the properties that the averaged velocity for one year is 100cm/s and the current direction is almost constant in the direction between the east and east-southeast.

DOI： 10.2208/jscejoe.74.I_928

Language：Japanese   Publisher：Journal of Geophysical Research: Oceans  

DOI： 10.1002/2017JC012876

Scopus

Language：Japanese   Publisher：Journal of Geophysical Research: Oceans  

DOI： 10.1002/2016JC012329

Scopus