66 George L. Mellor, Sirpa M. Hăkkinen, Tai Ezer and Richard C. Patchen
A
.... L
..... -, ......... - .. ~ .. ->o~,.~ . . . . . . . . . . . .
~ .. -" ...........
B
'--b
.... ~~~~~~~-L~~
o & 10 1& m m ~ » ~ ~ ~ M ~ M
IA",.,.
c
~~~I
aoo :=:::--:::::::14 _ _ "
--"--,,
,_I-~~~~-----'
- ' 0 - - \ 0
- - 8 _ _ 8
6--.
-
.... ~~~~--~~~~~
o II 10 10 201tt 3O:w.404toSOM eo 116
lAmwc
Fig. 4.4 North-south temperature cross sections at the center of the domain after 360 days
for (a) the z - grid, (b) the s grid and (c) the generalized s grid; AM =10 4 m 2 s -1.
The results were quite similar to the higher resolution, high viscosity results. However, the z - level grid produced numerically divergent results which was repaired
by increasing the number of vertical grid points from 11 to 21.
This is the place to also mention that POM usually operates with a non-linear,
Smagorinsky viscosity and diffusivity which has the advantage that its empiric al
constant is non-dimensional and nearly resolution independent and yields low values in regions where velocities are low. As noted by Derber and Rosati (1989), the