The North Atlantic Current (NAC) forms part of the boundary between the sub
tropical and subpolar gyres in the North Atlantic Ocean. The current has to
pographically controlled stationary meanders that appear to grow and decay.
A region cast of the current in the Newfoundland Basin contains water of m
ixed subpolar/subtropical properties, suggesting that there is exchange acr
oss the NAC. This study considers data from isopycnal RAFOS floats launched
in the NAC region from 1993 to 1995. We use the RAFOS data to define the "
frontal zone" as a pressure range where the jet is most likely to be found,
This definition requires a latitudinal dependence as the NAC shoals to the
north. Floats shallower and deeper than this range are defined to be on th
e subpolar and subtropical side, respectively. These definitions are used t
o estimate mixing that occurs between the current and its surroundings and
to estimate the relative quantity of exchange of water parcels between the
two gyres. Only small quantities of mass exchange from one gyre to the othe
r are found, but there is a distinct asymmetry leading to a mean flux from
the subpolar to subtropical sides. We also find that floats spend significa
nt time in the frontal region and are frequently exchanged between fast and
slow moving waters, particularly at the meander extrema. Diffusion, while
in the jet, leads to eddy cross-frontal exchange which is important for the
exchange of properties across the NAC.