Sea surface motion over an anticyclonic eddy on the Oyashio Front

NOAA-6 AVHRR (11-μm band) satellite images for 20 and 21 May 1981 have been used with an interactive computer algorithm to calculate surface flow components from displacement of surface pattern features and elapsed time. The results give estimates of speed and direction for motion along the Oyashio Front and over an anticyclonic eddy between the First and Second Oyashio Intrusions. Speeds of 54 cm/s were detected along the Oyashio thermal ridge. On the periphery of the eddy, speeds in the order of 25 cm/s were present while, nearer the center, motion at 14 cm/s was indicated. A composite picture of flow vectors overlayed on the image for 20 May infers streamline flow characteristics for the surface motion and shows surface isolation of the eddy from the Tohoku area to the south.