[MITgcm-devel] seaice adjoint and EVP

[Patrick Heimbach]

Hi again,

an update.
The exf_check_range problem was a different issue.

So, I suggest for seaice_evp to either revert to previous
SQRT(MAX(deltaC,SEAICE_EPS))
or to simply
SQRT(deltaC+SEAICE_EPS)

(same for deltaZ)

-Patrick



On May 14, 2007, at 7:53 PM, Patrick Heimbach wrote:

>
> Hi Martin,
>
> it's not clear why in seaice_evp.F (revision 1.8)
> you changed a sqrt expression that could never become zero
> to one that can. Your comment in CVS log:
>
> - replace SQRT(MAX(deltaC,SEAICE_EPS)) by MAX(SQRT(deltaC),SEAICE_EPS)
>   help the adjoint (this also changes the results slightly)
>
> actually does the opposite (produces NAN's).
>
> Problem is that when I revert to old expression I get a stop in
> exf_check_range.F
>
> So at least two things seem wrong in recent seaice_evp.F
>
> -Patrick
>
> ---
> Dr Patrick Heimbach | heimbach at mit.edu | http://www.mit.edu/~heimbach
> MIT | EAPS, 54-1518 | 77 Massachusetts Ave | Cambridge, MA 02139, USA
> FON: +1-617-253-5259 | FAX: +1-617-253-4464 | SKYPE: patrick.heimbach
>
>
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---
Dr Patrick Heimbach | heimbach at mit.edu | http://www.mit.edu/~heimbach
MIT | EAPS, 54-1518 | 77 Massachusetts Ave | Cambridge, MA 02139, USA
FON: +1-617-253-5259 | FAX: +1-617-253-4464 | SKYPE: patrick.heimbach