RAM is an air quality model based on the Gaussian-plume simplification of the diffusion equation which assumes time independence in the input meteorology and concentrations. The model is primarily used to determine short-term (one-hourto one-day) concentrations from point and area sources. The simulation is done using hourly meteorological data for periods ranging from one hour to one year. A default option is also available which may be used for regulatory applications. Use of this option automatically sets certain parameters to preassigned values for consistency with the United States EPA Guideline for Air Quality Models.