Nick Hodgskin

@fluidnumerics-joe getting some failing tests now with `FieldSet.add_constant_field`: `ValueError: Longitude DataArray 'lon' with dims ('XG',) is defined on the center of the grid, but must be defined on the F...

> at a minimum, a single point grid would be a single tracer point, which would give 4 vorticity points that form the boundary of the tracer cell. If you...

@fluidnumerics-joe full traceback Details ``` ============================= test session starts ============================== platform darwin -- Python 3.12.10, pytest-8.3.5, pluggy-1.5.0 -- /Users/Hodgs004/miniforge3/envs/parcels-dev/bin/python3.12 cachedir: .pytest_cache metadata: {'Python': '3.12.10', 'Platform': 'macOS-15.3.1-arm64-arm-64bit', 'Packages': {'pytest': '8.3.5', 'pluggy':...

Let's postpone this a couple days.... Working on a proposal that affects this

I've just rebased this and updated the API to line up with #2048 - ready for review.

> @fluidnumerics-joe getting some failing tests now with `FieldSet.add_constant_field`: `ValueError: Longitude DataArray 'lon' with dims ('XG',) is defined on the center of the grid, but must be defined on the...

Just implemented the review changes. Still a couple pending items above that we didn't discuss during our meeting @erikvansebille - after that I think we're good to merge.

> @VeckoTheGecko, I now realise that you also started #2014, which not only adds the datasets but also includes some other changes. Would it make sense to merge this PR...

> I think the tooling would be good to bring into here so I can work on that. Done

@erikvansebille not sure if you already have - would it be worth using the new tooling (`compare_datasets` at `parcels/_datasets/utils.py`) to double check the new datasets against the reference ones you...