ON THE VARIABILITY IN THE VERTICAL STRUCTURE OF THE DELAWARE COASTAL CURRENT

Previous studies have concluded that a distinctive feature of the buoy ancy-driven Delaware coastal current lies in the fact that the coastal current extends to the bottom and flows next to the heavier shelf wat er rather than on top of it. The present study examines two sets of ob servations conducted in 1990 and 1992. The 1990 observations are consi stent with previous findings, but the 1992 survey shows that the Delaw are coastal current forms a clear surface layer on top of the shelf wa ter. The wind does not provide an adequate explanation for the discrep ancy between the two surveys, as downwelling favorable winds were pres ent during both periods. The differences in the dyer discharge also ap pear inadequate in explaining the variability observed. The data sugge st that the variation in the tidal mixing characteristics associated w ith the spring-neap modulation may contribute to the observed differen ces between the two cruises. (C) 1998 Elsevier Science Ltd. All rights reserved.