[MITgcm-support] atmospheric exp broken ?

[Martin Losch]

Jean-Michel,

as far as I remember, the default for useNHMTerms=.true. stems from the 
historical fact, that before the inclusion of this flag, the terms 
where always included. That's a bug, but we didn't want to change the 
results of the verification experiments. So I strongly agree with you: 
Change the default for useNHMTerms and use them only where appropriate. 
None of the hydrostatic experiments should have these terms.

Martin

On Thursday, October 16, 2003, at 02:07  AM, Jean-Michel Campin wrote:

> 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
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