[Doc]: Add a regridding section to xCDAT FAQ

[jypeter]

Describe your documentation update

Easy/correct/consistent regridding is very important in our community (especially for multi-model work), and it would not hurt to mention regridding in the FAQ to help users find their way through the regridding related pages of the documentation. Either when users are already exploring the xCDAT site, or when they are using Google to find out how to regrid model data in Python

Regridding could be an entry point to xCDAT for people who don't know xCDAT but are looking for climate (model) data regridding

I suggest adding a Regridding section to the FAQ, with possibly the following sub-sections. A scientist or somebody more familiar with grids can surely some up with something better, but that's the idea

• Why is it important to be careful when regridding climate model data?
  • there are many different grid types, defined on a sphere (e.g CMIP6 ocean grids), and the builtin numpy regridding should not be used.
  • Some grids may have redundant data (aka halos). Hmm, I always wonder if this is handled correctly in regridding packages...
• How can I do horizontal regridding with xCDAT?
  • Link to the xCDAT horizontal regridding example
• How can I do vertical regridding with xCDAT?
  • Add something about pressure levels and relevant links?
• How can I do temporal regridding with xCDAT? This is possibly not phrased correctly, but it could be a place to add links to the climatology stuff

Oh, I just thought about something loosely related to this, but also useful. It could be useful to have an answer/example for that : how can I find the model data point closest to a givent (lat, lon) coordinate (e.g. field data)? That's a common question when people try to do some basic model/data comparison, and it could also provide a good entry point for users who don't know xCDAT

[jypeter]

When trying to look for a page with graphical model grids examples, I have found the following reference : Grids in Numerical Weather and Climate Models

I was actually looking for a page with some nice grid examples, but I still have not found anything better than this unmaintained gridspec page. The gridded home page lists grids types, but does not give any visual examples (the only thing that beginners need).

Maybe somebody will know a nice link