OBSERVATIONS OF THE BOUNDARY CURRENT SYSTEM AT 26.5-DEGREES-N IN THE SUBTROPICAL NORTH-ATLANTIC OCEAN

Five current meter moorings and four horizontal electric field records spanning June 1990-February 1992 are used to describe the mean struct ure and variability of the vertically averaged velocity field and volu me transport extending 425 km east of Abaco, The Bahamas, at 26.5 degr ees N. Examination of zonal and meridional velocity sections shows tha t, while meandering may explain part of the variability, there is subs tantial evidence for pulsation of the core DWBC velocity in the record . Intermittently strong northward flow is observed 225 km east of Abac o that is significantly coherent and out of phase with the currents cl oser to the boundary at periods of 50-100 d and longer, suggesting rec irculation. This is never observed 315 km offshore. At 380 km offshore and extending east at least 60 km, a strong, dominantly southward flo w is observed that Is coherent with both that near Abaco (in phase) an d in the intervening recirculation zone (out of phase) at long periods . The net mean transport (over 17 months) from Abaco to 325 km offshor e, spanning the recirculation region, is -17 Sv (Sv = 10(6) m(3) s(-1) ). The transport exhibits robust annual variability, and correction fo r the bias from the annual cycle in the 17-month dataset reduces the n et mean transport at 325 km to -13.6 Sv, Allowing for a northward Anti lles Current transport of 5.1 Sv yields a mean southward DWBC transpor t corrected for local recirculation of about 18.5 Sv, in approximate a greement with the thermohaline input from the northern North Atlantic. Comparison of transport time series from the Florida Current with tha t extending 125 km east of Abaco demonstrates significant and out of p hase coherence over the period range 100-259 d. The coherence decrease s as the Abaco transport is integrated farther to the east.