The Subtidal Lagrangian Current in Delawareʹs Inland Bays Under Low Wind Conditions

A series of field surveys were conducted in Delawareʹs inland bays to investigate the subtidal current in a Lagrangian framework. Drifters tracked by the LORAN-C and satellite (ARGOS) positioning techniques were released in January and April of 1992. The LORAN-C position data were first locally corrected, and then inter-compared with the concurrent ARGOS data. Subtidal currents were then examined based on LORAN-C position data obtained under low wind conditions. Current velocities, calculated from a central finite-difference algorithm, were generally less than 3•0 Cm s-1 in the bays, although larger currents (5•5 cm s-1) were observed in the vicinity of the Indian River Inlet. Correlation between the subtidal current and wind was also systematically examined. In January, subtidal current and wind were favourably correlated with a complex correlation coefficient of 0•78 and an average veering of about 3°. In April, however, a poor correlation was found between the current and wind vector time series.