Velocity measurements in the deep water of the western North Atlantic: Summary

In general our knowledge of the deep circulation of the ocean has been deduced indirectly either by a study of the geographical distribution of water masses represented by different temperature and salinity characteristics or by the use of the geostrophic equation. To obtain the pressure field needed in this equation requires, by present techniques, several days' work. Further, the performance of existing instruments precludes, in the face of extremely small pressure gradients, estimates of all but the larger scales of geostrophic motion. Velocities typically of the order of 1 cm/sec or less below a depth of 2000 meters in open ocean are suggested by the observations.