Flood Tide Circulation near Beaufort Inlet, North Carolina: Implications for Larval Recruitment

• Published in: Estuaries 1999-12, Vol.22 (4), p.1057-1070
• Main Authors: Churchill, James H., Hench, James L., Luettich, Richard A., Blanton, Jackson O., Werner, Francisco E.
• Format: Article
• Language: English
• Subjects: Aquatic ecosystems; Brackish; Coastal oceanography, estuaries. Regional oceanography; Coastal zone; Earth, ocean, space; Estuaries; Exact sciences and technology; External geophysics; Floods; Inlets; Invertebrata; Larvae; Marine; Mathematical models; Modeling; Navigation; Ocean currents; Ocean tides; Physics of the oceans; Pisces; Plumes; Salinity; Simulation; Simulations; Spring tides; Tides; USA, North Carolina; USA, North Carolina, Beaufort Inlet
• ISSN: 0160-8347; 1559-2723; 1559-2758; 1559-2731
• DOI: 10.2307/1353083

Drifter tracks and shipboard CTD observations have revealed a number of distinct features of the flood tide circulation carrying water through Beaufort Inlet, North Carolina. One of the most noteworthy of these features is a nearshore jet in the flow carrying water to the inlet on a flood tide. Characterized by a shoreward increase in longshore flow, the jet produces a narrow coastal zone over which water is carried into the inlet. The jet appears to be principally a tidal phenomenon, as it is closely reproduced by a tidally-driven barotropic numerical model. The model results also indicate the jet may be a near-inlet feature. Model simulations of spring tide conditions show the jet confined to within 4 km of the inlet mouth. Another observed phenomenon, which is reproduced by the tidal model, is a distinct splitting of the flow entering the inlet, in which water passing through a particular inlet segment tends to move up-estuary along a well-defined path. An observed flow feature not reproduced by the tidal model is an eastward skew of the region over which water is drawn into the inlet on a flood tide. This asymmetry is unrelated to the local wind. Modeling results from a previous study suggest it may be due to convergent flow at the edge of the low salinity plume issuing from the inlet. Taken together, the results of this and other recent studies in the Beaufort Inlet region reveal the importance of near-shore currents on the eastern side of the inlet in delivering oceanic-spawned larvae to the estuarine system connected to the inlet.