[MITgcm-support] Adjoins advection schemes

[Patrick Heimbach]

Actually, no, this part has been fixed a while back.
Should work now,
see up-to-date GAD_OPTIONS.h in pkg/generic_advdiff/ 
and
verification/global_ocean.90x40x15/input_ad/data

But you're right, the out-of-date comment in GAD_OPTIONS.h suggests otherwise.

p.

On Jul 2, 2012, at 2:35 PM, Matthew Mazloff wrote:

> And I'll add that the adjoint is usually run without multi-dimensional advection
> 
> GAD_OPTIONS.h:#define DISABLE_MULTIDIM_ADVECTION
> 
> If I remember correctly this is to prevent some nasty recomputations.
> 
> -Matt
> 
> 
> 
> 
> On Jul 2, 2012, at 6:41 AM, Patrick Heimbach wrote:
> 
>> 
>> Christopher,
>> 
>> our scheme of choice for the adjoint has become
>> 3rd-order direct space and time DST3 in non-flux limited form, i.e. scheme 30.
>> DST3FL (33) causes problems for certain applications, and we haven't followed up on this
>> (the obvious issue being how the limiters are formulated).
>> 
>> SOM is very memory-consuming, so we've staid away from this one for the adjoint
>> (which amplifies memory-consumption).
>> 
>> OS7MP is also currently disabled but might be worth a try
>> (would need some tweak though before it can be attempted).
>> 
>> -Patrick
>> 
>> On Jul 2, 2012, at 3:58 AM, Martin Losch wrote:
>> 
>>> Christopher,
>>> 
>>> the easiest way to find out is to have a look at gad_advection or gad_calc_rhs (the calls to GAD_*_ADV_X/Y). You'll see that most schemes "work" (i.e., they are allowed to be used) but in particular OS7MP (and I think SOM) doesn't work. From my experience I recommend using linear advection schemes (which rules out all flux limited schemes) for more accurate gradients.
>>> 
>>> Martin
>>> 
>>> On Jun 29, 2012, at 10:25 PM, Christopher L. P. Wolfe wrote:
>>> 
>>>> Hi all,
>>>> 
>>>> Does anyone know if there exists a list of advection schemes which are known to "work" with adjoint? I'm particular interested in the higher order schemes like OS7MP and SOM and their flux limited forms.
>>>> 
>>>> Thanks in advance,
>>>> Christopher
>>>> 
>>>> 
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>>> 
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>> 
>> ---
>> Patrick Heimbach | heimbach at mit.edu | http://www.mit.edu/~heimbach
>> MIT | EAPS 54-1420 | 77 Massachusetts Ave | Cambridge MA 02139 USA
>> FON +1-617-253-5259 | FAX +1-617-253-4464 | SKYPE patrick.heimbach
>> 
>> 
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> 
> 
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---
Patrick Heimbach | heimbach at mit.edu | http://www.mit.edu/~heimbach
MIT | EAPS 54-1420 | 77 Massachusetts Ave | Cambridge MA 02139 USA
FON +1-617-253-5259 | FAX +1-617-253-4464 | SKYPE patrick.heimbach


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