[Mitgcm-support] Re: Conservation z/z*

[mitgcm-support at dev.mitgcm.org]

Alistair,

> The exchange (point 3) shouldn't be needed so somewhere a loop range has
> been changed. That it didn't show up in any tests is bad; do we need a
> xz-slice test?
 
I think that the problem is this set-up itself:

When Spherical coordinate is used in a x-z plane, the domain is
closed in the Y direction and not cyclic (cf aim_EqChan).

I remember having problems with plume-on-slope because
it is also a x-z slice that is open (and cyclic) in the
y direction, but by chance (cartesian grid, no coriolis 
and so on) it works.

In this case, V is increasing gradually (because of the metric terms)
and this generate a drift in eta. This is perfectly right.

With no metric terms and phiMin=-.5, seems OK, no drift in eta & temp.
but i still not recommand to use an x-z slice with Spherical grid 
that is open and cyclic in Y direction.

Jean-Michel