A TIDAL MODEL FOR EASTERN JUAN-DE-FUCA STRAIT AND THE SOUTHERN STRAITOF GEORGIA

A three-dimensional, barotropic, finite element model is used to calcu late the tidal hows in eastern Juan de Fuca Strait and the southern St rait of Georgia. The harmonics of eight constituents are computed and compared with those from previous finite difference models and those f rom historical tide gauge and current meter observations. Root-mean-sq uare differences between observed and calculated sea level amplitudes are within 2.0 cm for all constituents, and the phases are within 4.0 degrees for all constituents except K-2. Horizontal currents from the model are found to reproduce the observed vertical variations in shear except in regions where stratification effects and internal tides exi st. In particular, the model representation of currents at six station s in the Canadian Tide and Current Tables (volume 5) is accurate. The pattern of tidal residual currents has much more detail than previous, coarser resolution models, and numerous eddies are predicted. Compute d energy flux fields reveal that over a 29-day period only 38% of the tidal power entering Juan de Fuca Strait is transmitted into the south ern Strait of Georgia, and of the 39% entering Hare Strait, 36% is dis sipated within the strait itself.