[MITgcm-support] atmospheric exp broken ?

[Jean-Michel Campin]

Hi, 

I choose to set "gravitySign" automatically, according to
the vertical coordinate that is used. 
I was thinking that such a minor modification will not affect
the output of the model. 
Instead, it appears that all the atmospheric experiments that
use the flux form are "broken":

Y Y Y Y  6 16 16 16 16 16 16 16 16 16 16 16 16  6  5  7  6 FAIL  adjustment.128x64x1
Y Y Y Y  4  7  7  9  8  7  6  8  7  4  4  6  5  4  3  3  5 FAIL  aim.5l_Equatorial_Channel
Y Y Y Y  8  8  7  8  8  7  7  6  7  4  5  6  6  5  4  3  6 FAIL  aim.5l_LatLon
Y Y Y Y  6 11  8  9  8 16 16 16 16  4  5  5  5  5  5  5  5 FAIL  hs94.128x64x5
Y Y Y Y  4  9  7  8  7 16 16 16 16  4  5  4  4  5  5 22  5 FAIL  hs94.1x64x5

because the default is to use non-hydrostatic metric terms 
(however, not very clear for me what non-hydrostatic metric terms are 
in a one layer adjusment problem with no momentum advection like in 
adjustment.128x64x1) that were "wrong" because the vertical 
coordinate was assumed to point in the wrong direction.

I would recommend:
1) to change the default value of useNHMTerms
and to set it to "false" instead of "true".
(was only introduced recently and was not in release.1)
2) for experiments where it make sense, to turn it on
so that the results are unchanged. 
3) for the other experiments where it's meaningless (1 layer) or 
wrong (atmosphere using mom_fluxform), to regenerate new output 
with the (new) default useNHMTerms=F.

comments and suggestions welcome.

Jean-Michel