Structure of the Gulf Stream and Its Recirculations at 55°W

Abstract

Abstract Two years of direct current and temperature observations from an army of 13 current meter moorings deployed near 55°W as part of the SYNOP (Synoptic Ocean Prediction) Experiment have been used to explore the spatial and temporal variability of the Gulf Stream from three points of view. In the geographic reference frame, mean eastward velocities were observed from the surface to 4000 m. There was no evidence of westward flow south of the eastward jet, suggesting that the Worthington recirculation gyre was located south of the array during this time period. Westward flow was observed north of the jet only at 4000 m, where it had a magnitude comparable to the mean Gulf Stream (5–10 em s−1). These data also indicate that the mean eastward jet is much more vertically aligned than was depicted in an earlier picture constructed from noncontemporaneous observations. In the Lagrangian, or streamwise, reference frame, it was found that, at the thermocline level, the width of the “average synoptic” Gulf Str...