72 
averaged wind vectors which has been observed at Muroran Meteorological 
Observatory (Fig. 6). In winter season, northwest direction is dominant component in 
this region as shown in Fig. 6. Both wind and surface current intend to vary 
simultaneously. After wind direction changed from northwesterly to southeasterly, 
surface current also changed from eastward to westward. However, this phenomena 
continue only for two - four days These events is coincidence the intrusion of Coastal 
Oyashio water to the Bay. We consider the change of wind southeasterly is an important 
parameter to the intrusion process of Coastal Oyashio water. The intrusion process of 
Coastal Oyashio water might not be continuously but intermittently. 
Acknowledgments 
We acknowledge useful support on temporally offering of HF radar site from Sawara 
Town Hall, Minami-Kayabe Town Hall, and Kinaoshi Fisheries Union. Satellite data 
relevant to this study were supplied by the Japan Weather Association. Hokkaido 
Newspaper Co. LTD. kindly provided a fund for promoting of this study. 
References 
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