Encoding 2m relative humidity in GribMetadata object

[mpvginde]

Hi,

I have a GRIB file containing 2m dewpoint temperature (2d) and 2m temperature (2t).
From this I want to calculate the 2m relative humidity and add it to the ekd.Fieldlist:

import earthkit.data as ekd
import earthkit.meteo as ekm

ds = ekd.from_source("file", "input.grib")

r2m = ekm.thermo.relative_humidity_from_dewpoint(
        t = ds.sel(param="2t").to_numpy(),
        td = ds.sel(param="2d").to_numpy()
    )

md = ds.sel(param="2d")[0].metadata().override(shortName="2r")
ds += ekd.FieldList.from_array(r2m, md)

But it seems the 2r key is not recognized by eccodes:

ECCODES ERROR   :  concept: no match for shortName=2r
ECCODES ERROR   :  concept: input handle edition=1, centre=ecmf
ECCODES ERROR   :  Please check the Parameter Database 'https://codes.ecmwf.int/grib/param-db/'
ECCODES ERROR   :  grib_set_values[0] shortName (type=string) failed: Concept no match (message 1)
ECCODES ERROR   :  concept: no match for shortName=2r
ECCODES ERROR   :  concept: input handle edition=1, centre=ecmf
ECCODES ERROR   :  Please check the Parameter Database 'https://codes.ecmwf.int/grib/param-db/'

However, it is in ECMWF's param-database.

Any ideas about the correct shortName for 2m relative humidity.
Or is this some GRIB1 vs GRIB2 issue?

Thanks in advance.
Also pinging @sandorkertesz for visibility.

Michiel

[sandorkertesz]

@mpvginde, it seems from the param-database that 2r is only a GRIB2 concept for ECMWF data. So you need to set the edition to 2. E.g.

md = ds.sel(param="2d")[0].metadata().override(edition=2, shortName="2r")