Influence of a Warm Eddy upon Current Structures in the Coastal Waters of Regions Between Oki and Noto

Abstract

The ADCP and CTD observations were made in July 2000, June and July 2001, in order to examine current structures in coastal waters off regions between Oki and Noto during the summer. An eastward current which had passed Through the Oki Strait and flowed toward coastal waters off Tango, that is, the coastal branch of the Tsushima Current, was observed in July 2000 and June 2001. Furthermore, another eastward current was found on the north side of the coastal branch off Tango; this current was connected with a southward one east of the Oki Islands. Off Kanazawa, however, the northern one of the two eastward currents did not exist in July 2000, and both were hardly found in June 2001. The reason is probably that a part or most of the eastward currents off Tango had turned anticlockwise and flowed westward along the margin of a warm eddy located off Kanazawa. In July 2001, an eastward current was clearly found along the coast from Tango to Noto, though it was very weak in the region from the Oki Strait to Tango. This eastward current seemed to originate from a current which had flowed southward in offshore waters and approached the coast of Tango. It was not from the coastal branch of the Tsushima Current. Weakness of coastal branch in July 2001 was probably due to the approach of a warm eddy to the Oki Islands. These observational results indicates that a warm eddy must influence the current structures in coastal waters off regions between Oki and Noto and that the path of the coastal branch, which is considered as stable, can be changed significantly by a warm eddy.