add landfrac for icon xpp

[bettina-gier]

Adding land fraction variables to ICON-XPP native reader

Adresses #2695

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.30%. Comparing base (3172e92) to head (a4e992c).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3169      +/-   ##
==========================================
+ Coverage   96.26%   96.30%   +0.03%     
==========================================
  Files         280      280              
  Lines       16258    16252       -6     
==========================================
  Hits        15651    15651              
+ Misses        607      601       -6     

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[schlunma]

I would recommend extending the list of automatically added scalar variables here:

ESMValCore/esmvalcore/cmor/_fixes/native_datasets.py

Lines 33 to 50 in 46124b9

	def fix_scalar_coords(self, cube: Cube) -> None:
	"""Add missing scalar coordinate to cube (in-place).
	Parameters
	----------
	cube:
	Input cube for which missing scalar coordinates will be added
	(in-place).
	"""
	if "height2m" in self.vardef.dimensions:
	add_scalar_height_coord(cube, 2.0)
	if "height10m" in self.vardef.dimensions:
	add_scalar_height_coord(cube, 10.0)
	if "lambda550nm" in self.vardef.dimensions:
	add_scalar_lambda550nm_coord(cube)
	if "typesi" in self.vardef.dimensions:
	add_scalar_typesi_coord(cube, "sea_ice")

This way, all variables from all models that use NativeDatasetFix benefit from this fix.

It also looks to me like the metadata you use is slightly different to the CMOR tables. For example, grassFrac expects the dimension typenatgr, which has the following metadata:

ESMValCore/esmvalcore/cmor/tables/cmip6/Tables/CMIP6_coordinate.json

Lines 2627 to 2649 in 46124b9

	"typenatgr": {
	"standard_name": "area_type",
	"units": "",
	"axis": "",
	"long_name": "Natural grass area type",
	"climatology": "",
	"formula": "",
	"must_have_bounds": "no",
	"out_name": "type",
	"positive": "",
	"requested": "",
	"requested_bounds": "",
	"stored_direction": "",
	"tolerance": "",
	"type": "character",
	"valid_max": "",
	"valid_min": "",
	"value": "natural_grasses",
	"z_bounds_factors": "",
	"z_factors": "",
	"bounds_values": "",
	"generic_level_name": ""
	},

[schlunma]

Thanks Tina, looks great! I think we can actually remove lots of code here (see comments). I also think you can re-add the tests you removed, they should work fine!

[bettina-gier]

Thanks Tina, looks great! I think we can actually remove lots of code here (see comments). I also think you can re-add the tests you removed, they should work fine!

I don't think those tests are necessary anymore since I'm not needing any fixes in ICON-XPP when moving these to the native dataset fixes. So they would just bloat?

[schlunma]

I would keep them because otherwise we don't test if the scalar coordinates are actually added (and I'm pretty sure the diff coverage won't be 100%). Having too many tests (if they are cheap!) can't hurt 😉

[schlunma]

Thanks Tina, looks great now! Tested with ICON-XPP data, everything works as expected. 🚀