MOORED OBSERVATIONS OF WESTERN BOUNDARY CURRENT VARIABILITY AND THERMOHALINE CIRCULATION AT 26.5-DEGREES-N IN THE SUBTROPICAL NORTH-ATLANTIC

A 5.8-year time series of moored current meter observations is used wi th hydrographic section data, CME model results, and gridded wind fiel ds over the North Atlantic to describe the mean structure and variabil ity of circulation and volume transports east of Abaco, Bahamas, at 26 .5 degrees N. A mean Antilles Current, with 5 Sv of northward transpor t, is confined against the Bahamas boundary in the upper 800 m and com bines with approximately 19 Sv of Florida Current transport to balance the Sverdrup interior circulation, and does not contribute to interhe mispheric exchange,The mean transport of the deep western boundary cur rent (DWBC) off the Bahamas is approximately 40 Sv, of which 13 Sv com pensates the upper branch of the thermohaline circulation, requiring a 27 Sv deep recirculation. Robust annual and semiannual cycles of meri dional transport are found in both moored observations and model resul ts with remarkable agreement in amplitude (+/-13 Sv) and phase. Maximu m northward transports occur in winter and summer, and minimums occur in fall and spring due to a predominantly barotropic response to remot e and local seasonal wind forcing. Transport variability on timescales less than semiannual is dominated by mesoscale eddies that propagate westward into the Bahamas boundary in the thermocline at periods of 70 -100 days, wave speeds of about 4 cm s(-1), and wavelengths of about 3 35 km. These events are frequently correlated with offshore shifts of the DWBC core.