Hello there.
I was researching something along these lines for the last couple of years for a personal map and this thread reminded me of it. So I began to think that surely there was out there some software that calculated all that for you. And after five minutes searching I've found a very promising website that explains along the lines I got stuck on (I got stuck on research and stopped making the (my) map, not the first time something like that happened, or the research was so detailed that passing all that to a map stopped being fun and started being boring or a chore).
I was researching the wind cells: Hadley cells, Ferrel Cells and Polar Cells (the wind that transports water and determines rainy or arid landscapes). To be honest, all those things they tell about how the climate is changing and all that, knowing how little we know about climate, is probably just made up BS to scare us, because more CO2 in the atmosphere won't stop the Hadley-Ferris-Polar Cells system. The climate is actually determined by the amount of water vapour in the atmosphere, and CO2 emmissions don't affect that. Sorry, got here on a tangent.
Here is the webpage I found:
https://space.geometrian.com/calcs/climate-sim.php
You enter your heightmap and the sim runs and calculates temperature and rain given where the cells are and how wind stripes water vapour off the ground, and you get the climates, I suppose.
I tested inputting a 1024x1024px b&w heightmap png of white noise obtained at
https://heightmap-generator.com/:
HeightmapClimateProject.png
Ugh that's too defined. I should erode it a bit with BlendR, but not worth it for this example.
With the URL modified so it would process the image correctly:
https://space.geometrian.com/calcs/c...24&height=1024
With the water level at 0.5 height, and Equatorial rotation and irradiance untouched (so that means, the same as Earth's).
And here is the output:
HeightmapClimateProject-biomes.png
It looks pretty good to me.
However it still has some limitations that are specified at the bottom of the page.