The long-timescale variability of the Deep Western Boundary Current (D
WBC) where it crosses under the Gulf Stream is analyzed using a 3-year
array of bottom current meters and inverted echo sounders. The relati
onship of this variability to fluctuations in the upper layer Gulf Str
eam is specifically addressed. At periods shorter than a year the DWBC
variability shows no relationship to the local Gulf Stream, 100-day f
luctuations show a pulsing of the DWBC transport, whereas longer-perio
d fluctuations are indicative of a meandering-type variability. By con
trast, on timescales greater than a year, variations in the orientatio
n and transport of the DWBC are directly related to such fluctuations
in the local Gulf Stream. The coupling reveals that the DWBC is forced
by changes in the Gulf Stream rather than causing such variations, wh
ich is in contrast to earlier modeling results.