Merge branch 'master' into 'main'

Signed-off-by: ED\cold2 <c.old@ed.ac.uk>

See merge request !45

environment.yml

 name: wavevalenv
 conda:
   environment: environment.yml
+channels:
+  - conda-forge
+  - defaults
 dependencies:
+  - python=3.7
   - cartopy=0.20.1
   - netcdf4=1.5.8
   - matplotlib
   - proj=8.1.1
-  - numpy=1.21.4
   - scipy=1.7.3
+  - numpy=1.21.4