Permalink : http://hdl.handle.net/2115/90249

JaLCDOI : 10.14943/bull.fish.73.1.15

KEYWORDS : island-shaded vortex;Okushiri Island;elliptical island;reduced gravity model

In this study, ADCP observations were carried out on a grid of ship routes with the expectation that the island-shaded vortex would be captured around Okushiri Island in summer. Although such snapshot observation did not reveal the vortex’s generation period, anti-clockwise vortex flows were indeed observed on the eastern side of the island, and a northward migration of its vortex was also inferred. The observed vortex could be easily reproduced by a reduced gravity model with an idealized elliptical island set up in the northward flow. The model experiments have newly shown the occurrence of alternating positive and negative vortices with two-periodicities, i.e., 2.7 days and its double cycle 5.4 days.