The images come from a paper named: "Wind Flow Models over Complex Terrain ..."
source: https://www2.dmu.dk/atmosphericenvironment/cost/docs/COST710-4.pdf

Also I propose you to sign up to MetEd (https://www.meted.ucar.edu/index.php)
where you'll find a lot of educational resources in meteorological topics.
You can use keywords (e.g. "NWP" for Numerical Weather Prediction)
and skill levels (e.g. "1" stands for easy) to narrow your search.