On the temporal variability of the surface Gulf Stream and near‐bottom flows

Abstract

Long (3–4 years) time series of the surface Gulf Stream position and near‐bottom flow south of Nova Scotia support earlier findings of a barotropic semimonthly periodicity in the region, a bimodal Gulf Stream path downstream of the New England Seamount Chain, and a seasonal shift in the Gulf Stream position. New results are (1) a marked reduction of the meridional shifts of the surface Gulf Stream when it is in its north position mode, (2) the semimonthly periodicity seeming to be related at times to the Mf tide (the most energetic long‐period tide), and (3) an energetic, highly coherent (but out of phase) motion with a near‐40‐day period in the surface Gulf Stream position and near‐bottom flow.