ERA5-Land cmorizer/fixes

[katjaweigel]

Is your feature request related to a problem? Please describe.
At the moment, there is an "on the flight" cmorizer for ERA5 data. In principle it also works for ERA5-Land, but there are some issues:

1. For ESMValCore: The fixes already existing for ERA5 are to a large extend also needed for ERA5-Land, I tested this for the variable pr (monthly) by simply copying
   esmvalcore/cmor/_fixes/native6/era5.py
   to
   esmvalcore/cmor/_fixes/native6/era5_land.py
   and it works, but there might be differences for other variables.
2. For the ESMValTool: Would it make sense, to include an ERA5-Land example to esmvaltool/recipes/cmorizers/recipe_era5.yml or make an own esmvaltool/recipes/cmorizers/recipe_era5-land.yml?

Would you be able to help out?
Partly

[valeriupredoi]

@katjaweigel probably best to include the land bit in the existng recipe_era5.yml unles there are solid reasons why it should be separate; are the fixes needed for all the ERA5 variables? If so, we can use the All functionality for all vars 👍

[katjaweigel]

I'm afraid the fixes are different, for different variables. For ERA5 there are already fixes for several variables in esmvalcore/cmor/_fixes/native6/era5.py, for ERA5-Land at least the fix there for pr is the same as for ERA5, but I'm not sure if this is true for the other variables.

[bouweandela]

copying esmvalcore/cmor/_fixes/native6/era5.py to esmvalcore/cmor/_fixes/native6/era5_land.py and it works

Rather than copying the file, I would recommend importing the required classes from it

but there might be differences for other variables.

Yes, the main part of the work would probably be to carefully read the ERA5(land) documentation and see what is needed

For the ESMValTool: Would it make sense, to include an ERA5-Land example to esmvaltool/recipes/cmorizers/recipe_era5.yml or make an own esmvaltool/recipes/cmorizers/recipe_era5-land.yml?

I think both options are fine.