the error of picard convergency failed

[CST1996]

Dear developer of Icepack,
I met with an error 'picard convergence failed' when I run the script icepack.submit
.
It will be helpful if you know something about the error.
Lookford to your reply.
Best wishes!

 

[dbailey]

A couple things to try. If this is right at initialization, you should look at your initial state information. What are you using to force Icepack? You can try reducing the timestep (dt). You can also try increasing the Picard iterations (nit_max). This requires a change to the code. However, changing the number of iterations is unlikely to help. The other thing you might try is to try a roundoff perturbation to an icepack parameter. For example, you could add 1.0e-8 to the r_snw value.

Dave

 

[CST1996]

A couple things to try. If this is right at initialization, you should look at your initial state information. What are you using to force Icepack? You can try reducing the timestep (dt). You can also try increasing the Picard iterations (nit_max). This requires a change to the code. However, changing the number of iterations is unlikely to help. The other thing you might try is to try a roundoff perturbation to an icepack parameter. For example, you could add 1.0e-8 to the r_snw value.

Dave

Thanks for your reply.
The forcing data I use are some atomspheric variables from ERA5. And the problem of picard convergence failed is proved to result from the unit mistake of forcing data, has been solved. And we run icepack successfully. However, we didn't find the output file of variables and we don't konw how to set where to output variables because it seems to be different from CICE whose output variables are set in namelist. So could you please tell me how to output variables.
Thanks.
Best Wishes!

 

[dbailey]

Icepack does not output netCDF files. The log files contain the variable information. You can use diagfreq to change the frequency of the output in the log files. To add a variable, you need to edit the Icepack driver code.