The dispersion models require the input of data:

Meteorological conditions such as wind speed and direction, the amount of atmospheric turbulence (as characterized by what is called the "stability class"), the ambient air temperature and the height to the bottom of any inversion aloft that may be present.
Emissions parameters such as source location and height, source vent stack diameter and exit velocity, exit temperature and mass flow rate.
Terrain elevations at the source location and at the receptor location.
The location, height and width of any obstructions (such as buildings or other structures) in the path of the emitted gaseous plume.
Many of the modern, advanced dispersion modeling programs include a pre-processor module for the input of meteorological and other data, and many also include a post-processor module for graphing the output data and/or plotting the area impacted by the air pollutants on maps.

The atmospheric dispersion models are also known as atmospheric diffusion models, air dispersion models, air quality models, and air pollution dispersion models.