Adding description of the GFS variables in the netcdf file

[sgana1]

Dear Alberto,
I have used your notebook to extract wind and pressure data from:
gfs = f"https://nomads.ncep.noaa.gov/dods/gfs_0p25_1hr"
I have produced a netcdf file with u10m, v10m and prmsl (pressure at sea surface level) using:
with xr.open_dataset(url) as ds:
(
ds[var1]
.isel(time=slice(*time))
.sel(lat=slice(*lat), lon=lon)
.to_netcdf(f"{date}_{run:02d}_uv10prmsl.nc")
)

I woiuld like to add the description of the variables contained in the netcdf file par example:
u10m: x-component of the wind at 10m
u10m: y-componet of the wind at 10m
prmsl: atmospheric pressure at sea surface level.

How to proceed please?

Thank you.

[albertotb]

Where would you like to add that description? As metadata in the NetCDF file?

[sgana1]

Yes, exactly! As metadata in the NetCDF file. Thank you.

[albertotb]

The NetCDF should already have some metadata, although not exactly that. You can print it in the notebook with something like this:

with xr.open_dataset(url) as ds:
   ds1 = ds[var1].isel(time=slice(*time)).sel(lat=slice(*lat), lon=lon)
   # similar for the other variables
   print(ds1["u10m"].attrs)

ds1.to_netcdf(f"{date}_{run:02d}_uv10prmsl.nc")

If you want to change that metadata, you can just assign something to it:

ds1["u10m"].attrs["my_key"] = "my_arbitrary_metadata"

You can also print this metadata with external tools to Python like ncdump.