Subtidal Flow Structure in Tidally Modulated Inlets

TitleSubtidal Flow Structure in Tidally Modulated Inlets
Publication TypeConference Proceedings
AuthorsLippmann, TC
EditorIrish, JD
Series EditorHunt, J
Conference NameCoastal Dynamics 2013
Conference DatesJune 24 - June 2
Conference LocationPlymouth, England, United Kingdom
KeywordsBoundary Layer Flow, Inlet Dynamics, Subtidal Currents, vertical structure

Observations of the vertical structure of subtidal currents were obtained on the inner shelf within Hampton and New River inlets located on the eastern U.S. seaboard. Currents on the inner shelf have complex vertical variation with speeds that attenuate over the water column and rotate with increasing depth up to 180 deg, and are strongly influenced by local winds. Within the primary inlet channels, subtidal currents are directed seaward and have reduced vertical structure, do not depend on local wind forcing, and are closely aligned with bathymetric contours. However, at New
River, surface currents aligned with a secondary channel 300 m to the north are directed landward, and have stronger vertical structure with near-bottom flows often heading in the opposite direction. The observed subtidal circulation provides a means to grossly estimate fresh water discharge, and has implications to morphologic evolution in the inlet.