Tidal Currents in Douglas Channel, British Columbia: Evaluation and Prediction

Douglas Channel is the principal shipping route between town of Kitimat and Pacific Ocean. Prediction near-surface currents crucial for safe tanker navigation cleaning-up oil spills. Three years current velocity data were collected at two moorings located 30 km apart. Spectral, wavelet, harmonic analysis measured throughout upper (40-m) lower (50–358 m) water columns indicated predominant influence semidiurnal (SD) tidal currents. In layer, wind density flows resulted in considerable seasonal interannual variability these Analysis SD variance reveals three major components: barotropic, coherent baroclinic, random baroclinic. The predictability depends on relative contribution stability first components. Tidal constants estimated one year used to predict other years; we found that mooring closer entrance Channel, 80 89% energy layer 89–93% can be forecasted, while channel head, numbers are smaller: 55–70% 79–89%, respectively.