[MITgcm-devel] seaice ridging: adjoint

[Martin Losch]

Hi Patrick,

this is indeed puzzling, because my changes should not be related to seaice_solve4temp.

But I cannot reproduce your results. How (or where) do you get the NaN’s with the TLM? 
I tried ./testreport -tlm -t lab_sea and everything looks good. 

What may have happened is that my changes have screwed up some initializations that are only required by TAF/TAMC.

Martin

On Apr 23, 2014, at 11:11 PM, Patrick Heimbach <heimbach at MIT.EDU> wrote:

> Hi Martin,
> 
> I haven’t looked in detail yet, but what’s suspicious is that the TLM gives NaN’s.
> Before your checkin, the TLM values were highly accurate (order 10^-8).
> Also NaN’s when I switch off seaice dynamics.
> 
> The TLM NaN’s in S/R seaice_solv4temp.F
> a bit after assigning t1 = tsurfLoc(I,J)
> 
> which then gets to mm_log10pi = -aa1 / t1 + aa2
> the TLM of which is NaN (I guess t1 = 0).
> Not sure why this is since that routine has not changed in 2 years.
> 
> If I switch to useMaykutSatVapPoly the TLM looks ok.
> 
> I’ll try to look more closely, but perhaps you have an idea.
> 
> -Patrick
> 
> 
> 
> On Apr 23, 2014, at 8:44 AM, Martin Losch <Martin.Losch at awi.de> wrote:
> 
>> OK, done, thanks,
>> 
>> The adjoint works but gives slightly different numbers. for SEAICE_ITD, there is no adjoint, as far as I can see.
>> 
>> Martin
>> 
>> On Apr 23, 2014, at 12:38 PM, Patrick Heimbach <heimbach at MIT.EDU> wrote:
>> 
>>> Hi Martin,
>>> go for it. I’m around, so can take a look.
>>> p.
>>> 
>>> On Apr 23, 2014, at 5:04 AM, Martin Losch <Martin.Losch at awi.de> wrote:
>>> 
>>>> Hi Patrick,
>>>> 
>>>> in preparation for real seaice ridging code, I am moving the regularization part (most of “PART I”) out of seaice_growth into a new routine.
>>>> 
>>>> Unfortunately this changes the adjoint gradient values (making the agreement with the FD gradient a little worse). All forward runs are OK:
>>>> G D M    C  A  F
>>>> e p a R  o  d  D
>>>> n n k u  s  G  G
>>>> 2 d e n  t  r  r
>>>> 
>>>> Y Y Y Y 16> 8<16 FAIL  global_ocean.cs32x15.seaice
>>>> Y Y Y Y 16> 7<16 FAIL  global_ocean.cs32x15.seaice_dynmix
>>>> Y Y Y Y 16> 5<16 FAIL  lab_sea  (e=0, w=18)
>>>> Y Y Y Y 16> 6<16 FAIL  lab_sea.noseaicedyn
>>>> 
>>>> The taf_ad.log is the same with and without my modifications (let alone line numbers and the extra routine), so no extra. I have no idea where to look. Can I check in my changes anyway and we have a look together?
>>>> 
>>>> Martin
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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
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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
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