Observations of wind-generated shoreface currents off Duck, North Carolina

Wind, wave and currents measurements at 9 and 14 meter water depths on the shoreface off U.S. Army Corps of Engineers Field Research Facility at Duck, North Carolina are presented. Coastal setup accompanied by southerly-setting alongshore currents and seaward cross-shore currents is developed during Northeasterly storms. Coastal setdown, with reversal currents, is generated by Southerly or southwesterly strong winds. However, while the current speed during Northeasterly storms is strongly correlated with the wind stress, this relationship does not hold during Southwesterly storms. This is attributable to the fact that downwelling-favorable Northeasterlies enhance the coastal jet and act to reinforce the coastal plume that often issues from the Chesapeake Bay.