The authors wish to thank the captains and crews of the R/V Endeavor, R/V Oceanus, and R/V Weatherbird II for their help in the deployment of the sound sources and collection of the observations. J. Valdes, B. Guest, and R. Tavares of the WHOI Float Operations Group are also gratefully acknowledged for their patience and skill in the preparation of the instruments. M. Mensel, then of IFREMER, kindly provided us with his float data processing software and answered many questions. A sound source deployed by K. Leaman of the University of Miami was useful in extending the tracking range of the floats. R. Curry provided valuable instruction in the use of HydroBase. Helpful discussions with R. Pickart, M. Spall, N. Hogg, and W. Smethie contributed to the development of the ideas presented in this paper. The work was supported under Grant No. OCE93-01448 from the National Science Foundation to the Woods Hole Oceanographic Institution.
Bower, A. S., 1991: A simple kinematic mechanism for mixing fluid parcels across a meandering jet. J. Phys. Oceanogr.,21, 173–180.
——, and T. Rossby, 1989: Evidence of cross-frontal exchange processes in the Gulf Stream based on isopycnal RAFOS float data. J. Phys. Oceanogr.,19, 1177–1190.
——, and H. D. Hunt, 2000: Lagrangian observations of the deep western boundary current in the North Atlantic Ocean. Part I: Large-scale pathways and spreading rates. J. Phys. Oceanogr.,30, 764–783.
——, H. T. Rossby, and J. L. Lillibridge, 1985: The Gulf Stream—Barrier or blender? J. Phys. Oceanogr.,15, 24–32.
Curry, R. G., 1996: HydroBase: A database of hydrographic stations and tools for climatological analysis. Woods Hole Oceanographic Institution Tech. Rep. WHOI-96-01, 44 pp. [Available from Woods Hole Oceanographic Institution, Woods Hole, MA 02543.].
Duan, J., and S. Wiggins, 1996: Fluid exchange across a meandering jet with quasiperiodic variability. J. Phys. Oceanogr.,26, 1176–1188.
Fine, R. A., 1995: Tracers, time scales, and the thermohaline circulation: The lower limb in the North Atlantic Ocean. Rev. Geophys., 33 (Suppl.—U.S. National Report to International Union of Geodesy and Geophysics 1991), 1353–1365.
——, and R. L. Molinari, 1988: A continuous Deep Western Boundary Current between Abaco (26.5°N) and Barbados (13°N). Deep-Sea Res.,35, 1441–1450.
Halkin, D., and T. Rossby, 1985: The structure and transport of the Gulf Stream at 73°W. J. Phys. Oceanogr.,15, 1439–1452.
Hogg, N. G., 1991: Mooring motion corrections revisited. J. Atmos. Oceanic Technol.,8, 289–295.
——, 1992: On the transport of the Gulf Stream between Cape Hatteras and the Grand Banks. Deep-Sea Res.,39, 1231–1246.
——, and H. Stommel, 1985: On the relation between the deep circulation and the Gulf Stream. Deep-Sea Res.,32, 1181–1193.
Hunt, H. D., and A. S. Bower, 1998: Boundary Current Experiment I & II: RAFOS float data report 1994–1997. Woods Hole Oceanographic Institution Tech. Rep. WHOI-98-06, 106 pp. [Woods Hole Oceanographic Institution, Woods Hole, MA 02543.].
Johns, E., R. A. Fine, and R. L. Molinari, 1997: Deep flow along the western boundary south of Blake–Bahama Outer Ridge. J. Phys. Oceanogr.,27, 2187–2208.
Johns, W. E., T. J. Shay, J. M. Bane, and D. R. Watts, 1995: Gulf Stream structure, transport, and recirculation near 68°W. J. Geophys. Res.,100 (C1), 817–838.
Joyce, T. M., C. Wunsch, and S. D. Pierce, 1986: Synoptic Gulf Stream velocity profiles through simultaneous inversion of hydrographic and acoustic Doppler data. J. Geophys. Res.,91 (C6), 7573–7585.
Lee, T., 1994. Variability of the Gulf Stream path observed from satellite infrared images. Ph.D. thesis, Graduate School of Oceanography, University of Rhode Island, 188 pp. [Available from University of Rhode Island, Kingston, RI 02881.].
Lozier, M. S., W. B. Owens, and R. G. Curry, 1995: The climatology of the North Atlantic. Progress in Oceanography, Vol. 36, Pergamon, 1–44.
——, L. J. Pratt, A. R. Rogerson, and P. D. Miller, 1997: Exchange geometry revealed by float trajectories in the Gulf Stream. J. Phys. Oceanogr.,27, 2327–2341.
Pickart, R. S., 1992: Water mass components of the North Atlantic Deep Western Boundary Current. Deep-Sea Res.,39, 1553–1572.
——, and N. G. Hogg, 1989: A tracer study of the deep Gulf Stream cyclonic recirculation. Deep-Sea Res.,36, 935–956.
——, and D. R. Watts, 1990: Deep Western Boundary Current variability at Cape Hatteras. J. Mar. Res.,48, 765–791.
——, and W. M. Smethie Jr., 1993: How does the deep western boundary current cross the Gulf Stream? J. Phys. Oceanogr.,23, 2602–2616.
——, M. A. Spall, and J. R. N. Lazier, 1997: Mid-depth ventilation in the western boundary current system of the sub-polar gyre. Deep-Sea Res.,44, 1025–1054.
Rogerson, A. M., P. J. Miller, L. J. Pratt, and C. K. R. T. Jones, 1999:Lagrangian motion and fluid exchange in a barotropic meandering jet. J. Phys. Oceanogr.,29, 2635–2655.
Rossby, H. T., and Coauthors, 1985: The isopycnal Swallow float—A simple device for tracking water parcels in the ocean. Progress in Oceanography, Vol. 14, Pergamon, 511–525.
——, D. Dorson, and J. Fontaine, 1986: The RAFOS System. J. Atmos. Oceanic Technol.,3, 672–679.
Samelson, R. M., 1992: Fluid exchange across a meandering jet. J. Phys. Oceanogr.,22, 431–440.
Smethie, W. M., Jr., 1993: Tracing the thermohaline circulation in the western North Atlantic using chlorofluorocarbons. Progress in Oceanography, Vol. 31, Pergamon, 51–99.
Spall, M. A., 1996a: Dynamics of the Gulf Stream/deep western boundary current crossover. Part I: Entrainment and recirculation. J. Phys. Oceanogr.,26, 2152–2168.
——, 1996b: Dynamics of the Gulf Stream/ deep western boundary current crossover. Part II: Low-frequency internal oscillations. J. Phys. Oceanogr.,26, 2169–2182.
Swallow, J. C., and L. V. Worthington, 1961: An observation of a deep countercurrent in the western North Atlantic. Deep-Sea Res.,8, 1–19.
Thompson, J. D., and W. J. Schmitz Jr., 1989: A limited-area model of the Gulf Stream: Design, initial experiments, and model/data intercomparison. J. Phys. Oceanogr.,19, 791–814.
Warren, B. A., 1981: Deep circulation of the World Ocean. Evolution of Physical Oceanography, Scientific Surveys in Honor of Henry Stommel, B. A. Warren and C. Wunsch, Eds., The MIT Press, 6–41.