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is note worthy, is a rapid decay of the ITW as the distance moves away from the generation
site. So, if in the vicinity of the continental slope, the ITW amplitudes are ~ 4 m, then for the
distance of 100 - 400 km from it, they do not exceed ~ 0.5 m. The latter circumstance may be
regarded as a manifestation of the ITW trapping by the continental slope and, in general, any
large-scale topographic irregularities, being consistent with the estimate of the ITW decay
scale.
Figures 8b,c, at which the spatial distributions of the baroclinic tidal energy density and
the diapycnal mixing coefficient along the same section are presented, are also interesting
because they reinforce the statement that the ITW in the Arctic Ocean are trapped by the
continental slope. The diapycnal mixing coefficient is computed using the model results and
the standard Osborn' formulae [Osborn, 1980] providing the upper limiting estimate of the
sought-for quantity. As can be seen, in the vicinity of the continental slope, the diapycnal
mixing coefficient may be larger than the molecular viscosity (~ 0.01 cm 2 /s) and the canonic
value of the vertical eddy viscosity in the main thermocline (~ 0.1 cm 2 /s) and much less than
the vertical eddy viscosity in the abyssal over rough topography (~ 10 cm 2 /s) (see, e.g., Polzin
et al., 1977; Ledwell et al., 1993, 1998, 2000). Clearly, the ITW-induced diapycnal mixing
coefficient is great as compared to the canonic value of the vertical eddy viscosity and may
make a contribution to the formation of the Arctic Ocean climate.
Figure 8. Vertical distributions of some ITW characteristics for the M2 wave along the section
indicated in Figure 1. a - ITW amplitudes (m); b - the averaged density of baroclinic kinetic energy
(J/m2); c - the diapycnal mixing coefficient (cm 2 /s); d - the maximum baroclinic tidal velocity (cm/s).
The regions with the southward direction of the baroclinic tidal velocity are shaded. The distance along
the section is given in km.
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