Abstract
We applied the Green’s Function approach to estimate control parameters of a numerical model for calculation of tidal currents and physical interpolation results from the radial M2 velocity observed by the Rader. We employed a 2-D model with wet-dry module using ROMS and calculated the M2 currents in the Ariake sea with 3 cases of which horizontal resolutions are 1/60, 1/120 and 1/240°. The four control parameters; (1) the magnitude and (2) the phase lag of tidal current ellipses and sea level from a global tidal model results, (3) the horizontal viscosity and (4) the sea bottom drag coefficient, were estimated by data assimilation of the radial M2 velocities by the RADAR and tidal gauge’s data into the model results. The estimated parameters suggest that (1) the magnitude and phase lag need not to change, (2) the drag coefficient is 1.8 × 10-3, (3) the viscosity ranges 10 — 50 m2 s-1. Moreover the magnitude, phase lag and the drag coefficient are independent on the grid resolutions. The physical interpolation from all the radar observations represents the horizontal distribution of the tidal currents and sea level in the Ariake Sea.
