Semidiurnal Tidal Currents Measured with Ocean Surface Radar around Isahaya Bay Mouth in Ariake Sound, Japan

Ariake Sound, in Kyushu Island of western part of Japan and connecting the small bay, Isahaya Bay, in the northwestern (Fig. 1) is strongly affected by large semidiurnal tide of which amplitude ranges from 3 to 5 m [3]. While Ariake Sound exhibits highly productive, red tides have occurred more frequently around the northern area of Isahaya Bay Mouth, causing damage to the sheries, recently [1]. The accurate and ne-scale tidal currents variability is generally important to evaluate water quality because estuary attributes such as salinity and temperature distributions are strongly affected by the tidal mixing and tidal exchange [4]. The motivation of the present work is the observation of ne-scale Semidiurnal Tidal Current (STC) variations around Isahaya Bay mouth in Ariake Sound with Ocean Surface Current Radar (OSCR), which enables us to measure surface currents with a high spatial and temporal resolution.