Some observations of internal wave current fluctuations at the shelf-edge and their implications for sediment transport

Observations of internal wave current fluctuations at a site on the European continental shelf are described. These have revealed current ‘pulses’ of regular tidal (M₂) phase which may be associated with internal tides generated at the shelf-edge. Current ‘pulses’ have been observed with amplitudes of 30 to 40 cm s^?1 superimposed on peak spring tidal currents of the order 60 to 70 cm s^?1. The measurements have shown that these fluctuations extended throughout the bottom mixed layer to within at least 2 m of the sea bed where they may play an important role in modifying sediment transport rates.