Year numbers in restarts and payu output directories

[MartinDix]

For starting historical runs (particularly ensembles) it's convenient to be able to specify a restart from somewhere in the PI control and have the year number set to 1850. The original CMIP5 scrpt setup did this. Should we add a startup script that changes the year number?

Output can also be simpler to understand if the payu counter also matches the true year number.

[JhanSrbinovsky]

How would this work - a 4 digit counter?

[MartinDix]

Payu links the restart files rather than creating copies, so the script would also have to work around this.

[aidanheerdegen]

You can set the start run number with the -i flag:

payu run -i 1850

See https://payu.readthedocs.io/en/stable/usage.html#running-your-experiment

You can also specify the restarts you want to use with

restart: path/to/restarts/PI_control/restartXXX

or use the --restart option to checkout which does this step for you:

payu checkout -b historical --restart path/to/restart

See https://payu.readthedocs.io/en/stable/usage.html#switching-between-related-experiments

If you have to make modifications to the restart files themselves then it becomes trickier. I guess that is what you're referring to above when talking about creating symlinks rather than copies?

I suspect this is very similar to what Scott did for the COECMS payu configurations

https://github.com/coecms/esm-historical/blob/master/scripts/warm-start-payu.sh