Updeated requirements* and ci/*py39* files.

ci/requirements_py39.yml

@@ -23,6 +23,7 @@ dependencies:
   - seawater    # optional
   - pandas
   - xarray      
+  - zarr
   - dask        
   - dask-jobqueue
   - dask-labextension
@@ -33,4 +34,4 @@ dependencies:
   - papermill
   - intake-esm
   - jupytext
-
+  - healpy

ci/requirements_py39_cartopy19.yml

@@ -23,6 +23,7 @@ dependencies:
   - seawater    # optional
   - pandas
   - xarray      
+  - zarr
   - dask        
   - dask-jobqueue
   - dask-labextension
@@ -33,4 +34,4 @@ dependencies:
   - papermill
   - intake-esm
   - jupytext
-
+  - healpy

requirements.txt

 numpy
-scipy
+matplotlib
+netcdf4
 xarray
+zarr
+pandas
 cmocean
+scipy
 ipdb
-netcdf4
-matplotlib
-cartopy
 ipywidgets
 jupytext
 pytest
+healpy

requirements_documentation.txt

+sphinx
+nbsphinx
+nbsphinx-link
+sphinx_copybutton
+pydata_sphinx_theme