I have a long way to go, but I can model the climate for continental areas


One of my forever goals has been a system where I can import an elevation map of one of my worlds and have the program spit out biomes. The true test of such a system is to give it real-world elevations and latitudes and see what happens, and I'm finally at a point where I can do that. Here's most of North America, and while it's not *accurate* it is getting into the right ballpark.

Looking at the American Southeast, there are swamps (dark gray-green for temperate swamps, dark green for tropical swamps) in Florida and along the coast, and warm forests (dark olive) further in. This gives way to shrubland (pale gray-green), then a cluster of prairie (light green), forest-steppe (medium green) and cold forest (dark green), where the humid Atlantic air hits the Rockies and drops its remaining moisture. Beyond that is mostly montane grassland and highland desert (light gray). The lower Mississippi is marshland (algae green), transitioning to floodplains by the coast (brown). The Greater Antilles are mostly tropical woodland (light olive), and Mexico is tropical woodland on the coasts and montane forest (medium green-gray) or rainforest (blue-gray) in the interior. Tropical rainforest (dark green) kicks in south of Guatemala.

North of \~40º N is not so good. The Pacific Northwest is mostly taiga (blue-green), because I'm not accounting for warming ocean currents yet. There are just a couple cells of temperate rainforest, near Portland. East of the Rockies is mostly steppe (yellow-tan) and cold desert (beige), because the wind is modeled almost entirely as coming from the west at these latitudes, and it loses almost all of its humidity over the mountains. Because the Midwest and Northeast are so dry, the Great Lakes aren't getting filled in, and there are salt flats instead (white).

I have a lot of work to do to get the wind system working well before I can call this done, but at least for a fantasy world I feel good about the results. I'm happy to share more, if anyone's interested, or trade ideas about how to model things without a supercomputer! I found a good source for high-resolution elevation data, and I can share the C# code I wrote to parse and transform it into 10-km hexes.