xESMF regridding showing repeated values at latitude poles

I am experiencing problems when regridding on a global grid in xesmf. Everything is working as it should, except for at the poles (latitudes -90 and 90), where it shows repeated values (2.58851004e+00, 2.58851004e+00, 2.58851004e+00, …) for each variable. I have also compared it with the CDO regridder to verify, and it showed differences of 0 at every lat/lon point, save for lats -90 and 90. Is there a fix for this?

I have attatched sample netCDF input data via zip file: test_input.zip Code:

import xarray as xr
import xesmf as xe

ds = xr.open_dataset('./test_input.nc4') 
ds = ds.transpose("time", "lat", "lon")
output_grid = xr.Dataset({'lat': (['lat'], np.arange(-90, 94, 4)),
                    'lon': (['lon'], np.arange(0, 360, 5)),
                    }
                )

regridder = xe.Regridder(ds, output_grid, 'bilinear',  periodic=True) #same problem for nearest neighbor regridding
ds_out = regridder(ds,keep_attrs=True)

print(ds_out)

You will notice, once ds_out is generated, evaluating ds_out[‘ZLCL’][:,0,:] or ds_out[‘ZLCL’][:,45,:] Will show all repeated values. These values correspond to lat = -90 and lat = 90.

[huard]

Thanks for the report, the example and test file. We’ve a bit of a backlog at the moment, will try to look into it next week.

[mtrimp2]

It is also worth noting, that when regridding the entire dataset, many variables yield different results. I tried to find a correlation to see if there is a sole issue (for example, the northward wind at 50m), but I do not believe it to be the case. Here is a complete output from nccmp diagnostics showing the differing variables, if that is helpful lears-mini_grass_global_regrid.json_comparison_regrid_global_all_vars.txt