[MITgcm-devel] changes in pkg/layers/layers_fluxcalc.F

[Jean-Michel Campin]

Hi Ryan,

I run a simple 2-D (y-z) test with the updated pkg/layers and the layers 
output (VH & Hs) are different, even where the bottom is flat and all 
hFac = 1 through the full column.
I look into your changes in layers_fluxcalc.F and the code line 303-304
seems wrong to me: When hFacS=1, I expect to find the same weighting as before
(MapFact, 1-MapFact) but instead I am getting (2-MapFact, MapFact-1).
Can you confirm this (I might have missed something) ?

The second thing is that I am not sure that we want to consider an hFacC
weighted averaged when computing the temperature/salt/rho at the
velocity location. In the case where the model uses the default
2nd order centered  advection scheme, the previous layers averaging (no hFacC
weight) was close to the model advection ; but with the new layers averaging
(with hFacC weight) this is no longer the case.
In other words, I am not convinced that this hFacC weighted averaged is 
more accurate for pkg/layers diagnostics.
I am curious to know why your made this choice (hFacC weight).

Cheers,
Jean-Michel