Date of Original Version
Low‐frequency longshore current fluctuations on the continental shelf off Georgia and their relationships with local atmospheric forcing and Gulf Stream displacement were examined for a 3‐month period from January to April 1978. (Acoustic travel time and bottom pressure measurements at a station on the continental slope were used to determine the depth of the main thermocline, as an indicator of Gulf Stream displacement.) On the middle shelf, current variability was dominated by local wind forcing at periods longer than 2 days, with very little Gulf Stream influence. Longshore wind stress was the main driving force at periods longer than 4 days, while cross‐shore wind contributed at shorter periods. In contrast, on the outer shelf, current fluctuations in the upper layer were highly coherent with Gulf Stream displacement at a 12‐day period, and marginally coherent with longshore wind at a 6‐day period. Linear regression analysis showed that Gulf Stream and local wind forcing accounted for most of the fluctuations in the upper layer over the shelf break for time scales greater than 5 days and at around 2 days. A low multiple coherence window at 2.8–5 days was probably due to Gulf Stream frontal eddies. In the lower layer over the shelf break the current fluctuations had a character intermediate between the upper layer currents (Gulf Stream dominated) and mid‐shelf currents (wind dominated).
Li, L., Wimbush, M., Watts, D. R., Brincko, A. J., and Lee, T. N. ( 1985), Gulf Stream and wind‐induced current variability on the Georgia continental shelf, winter 1978, J. Geophys. Res., 90( C2), 3199– 3210, doi: 10.1029/JC090iC02p03199.
Available at: https://doi.org/10.1029/JC090iC02p03199