66 
In the laboratory research on the coherent structure, it is experientially known that the 
periodic sheddings of discrete eddies are easily tuned with some external pulses forced periodically 
in the same frequency region (Davies et al. 1974). In some engineering devices, this resonance is 
applied to enhance the coherence of turbulent eddies for the use in turbulent boundary layer control. 
In our case of oceanic turbulence, external pulses are enforced from atmosphere; i.e. from 
the periodic passes of extratropical cyclones, a dominant factor of our site located just under the 
strong westerly. In the case of Gulf-Stream region, on the other hand, the westerly usually takes 
the course far north. In the coastwise boundary layer, we slightly expect the resonance mechanism 
because of the lacks in the periodic external forcings as well as in the fully matured Giant-Cusps. 
4. Concluding remarks and acknowledgements 
This indirect approach to the Kuroshio has been designed to translate into action the 
geophysical research scheme on the oceanic turbulence around Japan-Islands-Chain, that was 
urgently appealed in 1970s by Yoshida (1976). Even if so much advanced measuring tools were 
deployed in the field some day, we would confront a decisive restriction, too short a time duration 
of measurements. Time scale is wide from days to years. The process is essentially nonlinear and 
tunes with external forcings from air and solid-earth, the phase of which is rather random or 
catastrophic. To obtain ordinary statistics assuming stationary random process, we must wait 
almost comparable to our life time. Some specific statistics should be devised aided with a GIS, in 
which various kinds of data sets shall be integrated; e.g. NOAA/AVHRR data, K-U index , old 
fishermen's knowledge data or topographic, atmospheric and hydrographic data etc. Altimetric 
data, SeaWIFS data, shore-based HF or TOH radar data shall follow soon in future. 
We owe to US tax payers and to Prof. Hiroshi kawamura (Tohoku University) easy acess to 
the HRPT data of NOAA/AVHRR. This research is ongoing supported by the Grant-in-Aid for 
Scientific Research (No. 07650607) from the Ministry of Education, Science and Culture, Japan. 
5. References 
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Springer-Verlag Berlin Heidelberg, pp. 19-45, 1983 
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