Clarification on variable naming conventions for inference inputs

[JGrassi97]

Hi, thanks for the great work on ACE
I’m trying to understand how variable names in the checkpoint map to physical variables and vertical levels.
For example, variables like:
• air_temperature_0 … _7
• specific_total_water_0 … _7
• eastward_wind_0 … _7
make it unclear which actual vertical levels they correspond to (e.g. pressure levels, ordering, etc.).
More generally, it’s a bit difficult to understand how the variable names used in the checkpoint relate to:
• physical variable definitions
• vertical coordinates / levels
Is there any documentation or mapping that makes this explicit?

Thanks in advance!

[oliverwm1]

Hi @JGrassi97, there is some metadata and vertical coordinate information serialized along with the model weights. The exact details of what was serialized has changed a bit over course of development. But if you use fme.ace.stepper.load_stepper to open the checkpoint, you should be able to find it under the _dataset_info attr. Alternatively you can also reference the papers corresponding to particular checkpoints for the definitions of the variables used.