[MITgcm-support] balancing the heat equation

[Nicolas Wienders]

	Miss Byrd,


> Hi Allison,
> without checking details in the code I would suggest that you use  
> the diagnostics package for diagnosing the different contributions.  
> As far as I can see, the diagnostics are all available:
> dT/dt:
>       diagName  = 'TOTTTEND'
>       diagTitle = 'Tendency of Potential Temperature'
> uTx/vTy/wTz: 'ADVx/y/r_TH '
> KTxx/yy/zz: 'DFx/y/rE_TH ' (and 'DFrI_TH ' for the implicit part  
> which is relevant for KPP)
> Then there is the non-local term in KPP, which can be diagnosed  
> with 'KPPghat '; however that is not the contribution to diffusive  
> flux, and you'll have to alter the code a little to get that  
> contribution with the diagnostics package. Here's a hack that  
> abuses DFrE_TH for this purpose: In gad_calc_rhs.F find the calls  
> to KPP_TRANSPORT_T etc. They are within a #ifdef ALLOW_KPP/#endif  
> block. just before this there is a diagnostics call (#ifdef  
> ALLOW_DIAGNOSTICS/#endif). Just exchange the order of these two  
> blocks and DFrE_TH will give you the flux-contribution of the non- 
> local term (but the explicit diffusive flux will be overwritten and  
> not diagnosed, which is only OK, if you are using KPP without  
> GMREDI!).
> A better solution is to add  a new diagnostic and insert it after  
> the calls to KPP_TRANSPORT_T etc).



All this means that we will have to:

	+ modify the code

	+ include the diag package

	+ recompile

	+ run the code with these modifications.

	
We will need His Most Serene Highness Dewar to tell us in what  
configuration
and for what period of time/sampling to do that.