FY 1975

Linearized long wave, numerical model of the Hawaiian Islands

Bernard, E.N.

Hawaii Institute of Geophysics, HIG-75-13, 45 pp (1974)

A numerical model simulating linearized long waves interacting with the seven major Hawaiian Islands is presented. A spline interpolation scheme is utilized to convert the actual soundings of the island bathymetry to a 5.6-km-square grid closely approximating the topography of the islands. A time marching, central difference, explicit scheme is used to evaluate the wave field by the linear, Eulerian equations of motion and continuity in Cartesian coordinates for a frictionless homogeneous fluid. The condition of nonnormal flow is employed at the island shorelines and a localized interpolation technique is utilized at the outer boundary to simulate a free-flow boundary. Verification of the numerical procedure is accomplished by agreement with analytic solutions of steady-state problems involving wave interaction with geometric islands in both constant and variable depth cases. At test run from the north is illustrated and selected wave records are shown.