html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue
https://github.com/pydata/xarray/issues/508#issuecomment-1144845488,https://api.github.com/repos/pydata/xarray/issues/508,1144845488,IC_kwDOAMm_X85EPPSw,2448579,2022-06-02T13:10:04Z,2022-06-02T13:10:04Z,MEMBER,Yes that is correct,"{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,98587746
https://github.com/pydata/xarray/issues/508#issuecomment-553940815,https://api.github.com/repos/pydata/xarray/issues/508,553940815,MDEyOklzc3VlQ29tbWVudDU1Mzk0MDgxNQ==,2448579,2019-11-14T15:33:52Z,2019-11-14T15:33:52Z,MEMBER,"Thanks for tackling this very important issue @scottcha !
```
from .dataarray import DataArray
new_array = DataArray(coords=ds.coords, dims=ds.dims)
ds[k] = new_array
```

Instead of creating a DataArray we only need to create a `Variable` (https://xarray.pydata.org/en/stable/internals.html#variable-objects).

I would instead try `full_like(example_variable, fill_value=np.nan)` (import `full_like` from the appropriate file). The trick would be figuring out what `example_variable` is. Maybe like this? (there may be some clever way to avoid the two loops)

``` python
variables = []
for ds in datasets:
    if k in ds.variables:
         filled = full_like(ds.variables[k], fill_value=np.nan)
         break

for ds in datasets:
    if k not in ds.variables:
        variables.append(filled)
    else:
        variables.append(ds.variables[k])

vars = ensure_common_dims(variables)
```

Please send in a PR with any progress you make. We are happy to help out. We have some documentation on contributing and testing here: https://xarray.pydata.org/en/stable/contributing.html","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,98587746