0624/polar quivers notebook

[b-barton]

Pull request checklist

Please check if your PR fulfills the following requirements:

• [x ] Tests for the changes have been added (for bug fixes / features)
• [x ] Docs have been reviewed and added / updated if needed (for bug fixes / features)
  • Some docs updates need to be made in the COAsT-site repo, in a separate PR. See contributing to documentation for details.
• [x ] Build (./build.sh) was run locally and no errors reported. NB not sure about this requirement: GitActions test this
• [x ] Lint (pylint .) has passed locally and any fixes were made for failures. NB not sure about this requirement: GitActions test this with black

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• [x ] Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• [x ] Other (please describe): Example notebooks

What is the current behavior?

Issue URL: #

What is the new behavior?

New example notebooks for the Arctic domain. This shows how to plot quivers and use the functions to make adjustments for NEMO curvilinear grid and cartopy polar projection. An additional notebook has been added for plotting the new example dataset (a cropped version of a global NEMO run) for the Arctic. This includes plotting contours over the arctic which are not straight forward. Additional plotting helper functions have been added to plot_util for making polar plots and for plotting contours on polar plots. Tests included for these.

Checklist

• [x ] Code compiles correctly
• Created tests which fail without the change (if possible)
• [~ ] All tests passing (pip install . && pytest unit_testing/unit_test.py -s)
  Same as before there are two tests I'm unable to run on my machine "test_gridded_initialisation" and "test_tidegauge_methods" (Windows things). The rest passed. I have no reason to think test_gridded_initialisation or test_tidegauge_methods would fail. Git actions tests keeps failing but I'm not sure why.
• Extended the README / documentation, if necessary
• [x ] Added myself / the copyright holder to the AUTHORS file

Does this introduce a breaking change?

• Yes
• [x ] No

Other information

[jpolton]

Hmmm. There is definitely a problem with installing cartopy on the GitAction runners. The problem looks like the containers are trying to install cartopy from source, which is hard. The internet recommends using conda to install cartopy. However, the runners use a pip install method that uses the requirements.txt file. Perhaps it would be easier if the runners copied the environment.yml approach with slip pip and conda install methods? Hmmm

[jpolton]

Previously we installed cartopy but not pyproj. The problem now might be it is hard to mix these two packages as cartopy has pyproj under the hood...

Maybe explicit use of pyproj can be avoided: https://clouds.eos.ubc.ca/~phil/courses/atsc301/html/cartopy_mapping_pyproj.html looks like it might be possible
Then we would revert back to previous build requirements

[soutobias]

@jpolton @b-barton , I've made code updates by replacing cartopy with pyproj. Additionally, I've incorporated changes in the code to address pylint-related issues. All tests are passing, except for the pylint test. However, I've already addressed the pylint issue in a separate branch, which will resolve this issue. I also updated the example files and now they have only 5 mb.

[soutobias]

Looks good for me