Estimates of Geostrophic Surface Currents in the South Atlantic Bight

The determination of long-term trends in the behavior of the Gulf Stream is critical to understanding the meridional heat transfer cycle and associated global climate change. In this study, in situ current measurements from cross-stream transects of an Acoustic Doppler Current Profiler (ADCP) were used in conjunction with satellite altimetry data to obtain accurate estimates of Gulf Stream surface geostrophic current within the South Atlantic Bight (SAB) between 1992 and 2004. Analysis of time series data reveals that the magnitude of the geostrophic flow varies seasonally and that the seasonally averaged velocity was greatest following the intense 1997–1998 El Niño. Because of the relatively small fluctuations in the Gulf Stream's path, our analysis provides a method for accurate, long-term measurements of Gulf Stream currents for this region of the SAB.