rithms in the
-coordinate system with a spatial resolution allowing for reproducing synoptic eddies were per-formed in two versions: with the Arctic Ocean and without it (boundary along 78°N). They showed that the
account for the water exchange with the Arctic is fundamentally important for reproducing jet dynamics at the
western boundary of the Atlantic down to the subtropical zone. The influence of the conditions at the liquid
boundary that separates the Atlantic and the Arctic extends not only over the subarctic area [29] but is also
“transferred” by the Labrador Current and the Slope Water Current (SWC) to the area of the Gulf Stream proper.
One cannot properly describe the detachment of the Gulf Stream from the coast without adequate reproducing
of the Labrador Current and SWC. An hypothesis is posed that the location of the detachment region at 35°N
is caused by strong vertical motions at the interface between the SWC and the Gulf Stream jet with horizontal
velocities that are almost equal to those at the exit from the Florida Strait. A comparison of the model circulation
with that retrieved from the hydrological data and the drift of neutral buoyancy floats [14, 22] showed both qual-
itative and quantitative coincidences of the features of the northward warm water transfer such as the streamline
around the so-called northwestern “corner” (motion “along the topography”) and the jet-wise transport of these
waters from Labrador to the northeast inside a kind of “pipeline,” which is limited in the upper baroclinic layer
1 km thick by mean velocity contour lines of about 10 cm/s. A comparison between the experimental [19] and
model fields of the ocean level showed that, at the absence of direct representation of the water (mass) exchange
between the Atlantic and the Arctic Ocean, the decrease of the gradient velocities in the Gulf Stream may reach
30%.