Improve regional climo plots

[wwieder]

We can make regional climatology plots, thanks @megandevlan !

A number to TODOs remain (note each of these could be it's own issue)

• region_list now required on config files, should be added to template examples.
  • Can we include an option for - all?
• Allow user control of climo variables plotted, or just read off config files?
  • currently hard coded list
• check that all varaibles have climo files
  • could be avoided if variables are read off config file
• add option so that this works with a structured grid too
• make sure that climo's are being plotted with the preferred units
  • derived from scale_factor and new_units in lib/ldf_variable_defaults.yaml
• add in observations (need to regrid/area weight)
  • see example here
• Improve how to display the figures on the website
• Clean up unused code in regional_climatology script

Assistance required?

Yes, there aren't enough hours in the day!