→Vapor Flow: typo
The movement of gaseous material (either water vapor or CO<sub>2</sub>) across the surface of the object is simulated with a method similar to the one used to simulate [[Temperature Calculation#Surface Temperature|heat diffusion]. Vapor flows from areas of high density to areas of low density, so the vapor in a single point on the surface map of an object may spread or [https://en.wikipedia.org/wiki/Diffusion diffuse] into nearby points, and the vapor in those points may spread to the first point. Universe Sandbox calculates this diffusion by using the [https://en.wikipedia.org/wiki/FTCS_scheme FTCS method].
In addition, the speed and direction with which vapor flows across the map is affected by a simulated [https://en.wikipedia.org/wiki/Coriolis_force#Meteorology Coriolis force] and the size of the object, as well as the Elevation difference between regions of the surface.