f
-
f
-
Observations and Numerical Models
271
-----.------0"
20"
AO"
AFig. 4.12.6. Depth contours and streamlines on the (Je = 26.0 surface from the calculations of Cox
(1985). a Coarse-grid calculation of the depth of the surface. bAs in a except for the fine-resolution
case. c Montgomery function for the coarse-grid case. d Montgomery function for the fine-grid case
models in which the net vort1c1ty input is very small, and therefore the
problems of basin scale vorticity balances as described in Chapter 2 are avoided
by fluxing potential vorticity from the subtropical gyre to the subpolar gyre
rather than through the lateral boundaries. The calculations are carried out
with the circulation of the North Atlantic in mind.
Figure 4.12.6 shows some of the principal results of the two calculations.
Panels a and c show the depth and Montgomery function on the a0 = 26.0
density surface for the coarse-resolution case (with no eddies) while panels b
and d show the same quantities for the case in which the eddies appear and are
resolved by the model. In both cases the results of the numerical model are
qualitatively similar to those of the analytical theory. The depth of the density
surface is the familiar sloping bowl at whose northern boundary is the outcrop
line. The streamlines of the flow, given by the Montgomery function isolines,
clearly display the three regions described by the theory. In both the eddy-free
and eddy-resolving models there is a band of streamlines in the eastern part of
-
f
-
Observations and Numerical Models
271
-----.------0"
20"
AO"
AFig. 4.12.6. Depth contours and streamlines on the (Je = 26.0 surface from the calculations of Cox
(1985). a Coarse-grid calculation of the depth of the surface. bAs in a except for the fine-resolution
case. c Montgomery function for the coarse-grid case. d Montgomery function for the fine-grid case
models in which the net vort1c1ty input is very small, and therefore the
problems of basin scale vorticity balances as described in Chapter 2 are avoided
by fluxing potential vorticity from the subtropical gyre to the subpolar gyre
rather than through the lateral boundaries. The calculations are carried out
with the circulation of the North Atlantic in mind.
Figure 4.12.6 shows some of the principal results of the two calculations.
Panels a and c show the depth and Montgomery function on the a0 = 26.0
density surface for the coarse-resolution case (with no eddies) while panels b
and d show the same quantities for the case in which the eddies appear and are
resolved by the model. In both cases the results of the numerical model are
qualitatively similar to those of the analytical theory. The depth of the density
surface is the familiar sloping bowl at whose northern boundary is the outcrop
line. The streamlines of the flow, given by the Montgomery function isolines,
clearly display the three regions described by the theory. In both the eddy-free
and eddy-resolving models there is a band of streamlines in the eastern part of