Initial gradient norm, Gnorm = NaN

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wavewatch
Posts: 7
Joined: Thu Nov 14, 2013 1:51 am
Location: institute of oceanology

Initial gradient norm, Gnorm = NaN

#1 Post by wavewatch » Wed Mar 28, 2018 1:38 am

Hi, everyone!

When I run my IS4D-Var model, I got the error at the first inner loop. The log file shows:
……
<<<< Descent Algorithm >>>>

(001,000): Initial gradient norm, Gnorm = NaN
……
TLM: GET_STATE - Read state initial conditions, t = 1 00:00:00
(Grid 01, File: wc13_itl.nc, Rec=0001, Index=1)
- free-surface
(Min = NaN Max = NaN )
- free-surface, open boundaries
(Min = NaN Max = NaN )
- vertically integrated u-momentum component
(Min = 0.00000000E+00 Max = 0.00000000E+00)
- vertically integrated u-momentum component, open boundaries
(Min = NaN Max = NaN )
- vertically integrated v-momentum component
(Min = 0.00000000E+00 Max = 0.00000000E+00)
- vertically integrated v-momentum component, open boundaries
(Min = NaN Max = NaN )
- surface u-momentum stress, adjusted tl_ustr
(Min = NaN Max = NaN )

……

STEP Day HH:MM:SS KINETIC_ENRG POTEN_ENRG TOTAL_ENRG NET_VOLUME
0 1 00:00:00 NaN NaN NaN 1.159856E+16
……

I don’t know why the initial gradient norms is NaN.
I attached my log file for your convenience.
Thank you for your help.
Attachments
output.log
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ckerry
Posts: 10
Joined: Wed Sep 15, 2010 1:59 pm
Location: UNSW Australia

Re: Initial gradient norm, Gnorm = NaN

#2 Post by ckerry » Sun Jul 22, 2018 11:45 pm

Hi,
I'm wondering if you found the solution to this problem?
I'm having the same error.
Thanks

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