Author(s): Andhita Triwahyuni, Koji Asai
Linked Author(s): Andhita Triwahyuni
Keywords: Kanmon strait, FVCOM, tidal current, particle tracking method, water exchange
Abstract: The Kanmon strait is a water body that separates two of Japan's four main islands, the south-western edge of Honshu Island and the north of Kyushu Island. It connects the Hibiki Nada in the Sea of Japan and the Suo Nada in the Seto Inland Sea. This strait is important for international shipping, and one of the most difficult strait for ship navigation. A numerical simulation of Kanmon Strait is developed by using Finite Volume Coastal Ocean Model (FVCOM) in order to understand the seawater exchange influence by M2 tidal component. By identifying the surface water exchange from the numerical simulation result, tidal current shows that the current tends to flow eastward during ebb tidal condition and westward during flood. The maximum of tidal current velocity can reach 2. 92m/s during ebb tide and 3. 07m/s during flood tide. A residual current pattern of Kanmon strait shows there are clockwise water circulation at the center of the strait and anticlockwise on both the strait mouths with a maximum velocities about 0. 51m/s. The residual current pattern can be assumed to be occurred by the influence of coastal geometry shape and bathymetry. The 30 days simulation of Lagrangian particle distributions of Kanmon Strait shows that particles released on the eastern side of the strait tend to move westward more than the western side particles move eastward. In general, the numerical simulation result influenced by only M2 tidal component showed that surface seawater exchanges in Kanmon Strait are dominated by the westward movement. This is shown by higher westward current velocity during flood than the eastward current during ebb. Residual current is dominated by the southwest direction current, and also by the Lagrangian particle distribution where the percentages of particles moving to the Hibiki Nada are larger than to the Suo Nada
Year: 2017