Journal of Oceanography, Vol. 53 (No. 6), pp. 563-570, 1997
Hidetaka Takeoka1, Atsushi Kaneda2 and Hiroshige Anami3
1Department of Civil and Environmental Engineering, Faculty of Engineering, Ehime Univ.,
3 Bunkyo, Matsuyama 790-77, Japan
2Fuyo Ocean Development & Engineering Co. Ltd., Torigoe 1-8-2, Taito, Tokyo 111, Japan
3Marine Fisheries Research Center of Ohita Prefecture, Kamiura, Nankai-gun, Ohita 879-26, Japan
(Received 10 March 1996; in revised form 2 June 1997; accepted 6 June 1997)
Abstract: Hydrographic observations in Uchiumi Bay and Saiki Bay along the coasts of the Bungo Channel, Japan, revealed structures like a tidal front at the mouths of both bays. These frontal structures are stable and can be classified as a tidal front. For these tidal fronts, the horizontal contrast of the current speed is in an opposite sense to the usual tidal fronts; that is, the regions of weaker tidal currents are vertically mixed and those of stronger tidal currents are stratified. The regions of weaker tidal currents are supposed to be efficiently mixed by the three-dimensional processes driven by the effect of horizontal geometries. Therefore, these fronts can be called tidal fronts induced by the contrast of the vertical mixing efficiency.