Restart fails with ice variables not found

Hello, I am new to NEMO so apologies if this is a beginner question!

I am trying out a colleague’s configuration on a different HPC facility, using NEMO 4.2. When I try to restart with the restart files he provided, it fails with the following errors:

iom_varid, file: ./, var: e_s_l02 not found

and similarly for var: sxc0_l02, syc0_l02, sxxc0_l02, syyc0_l02, sxyc0_l02.

Indeed these variables are not in, but how do I tell the code not to look for them?

Many thanks

Hello Kaitlin,

It seems that the restart files come from a simulation where the sea ice model had 1 layers of snow (namelist parameter “nlay_s”), and that you are attempting to use them to restart a simulation which would have 2 layers of snow. The model does not find the variables to initialize the second snow layer.

I don’t think there is an easy way around it, other than having the same number of snow layers in both simulations.

Hi Antoine,

Thank you for your quick reply. Yes, I have nlay_s=2. But strangely enough the problem has now gone away - it reads the restart and starts just fine despite the mismatch in snow variables. I made a number of changes to the namelist all at once (started using Nico Jourdain’s tools to automatically edit the namelist) so something there must have done it, but I’m not yet sure what.


If your restart has only 1 ice layer, and you are looking for 2, then your model should fail in the version 4.2. In the “main” branch, the model just prints a warning and pretends you are starting from scratch and uses the namelist parameters defined in namini. To change the reading of your restart you need to code something in icerst.F90 routine but it will not be super neat.

Hi clem,

Thanks for the advice, that’s good to know. My restart file does have 2 ice layers, and includes some variables like sye_l02, etc. I think the difference is it does not have 2 snow layers. So, it does not fail, and it doesn’t seem to print any warnings either.