When using the US EPA AERMOD model, it is often necessary to give the same properties to several sources. For example, for a facility that has seasonal operations, the same variable emission rate may apply to many sources. Rather than entering the same information repeatedly, it is possible to use source ranges to specify a series of sources to which the same information will be applied.
In last month's modeling tip we discussed the emission rate and modeled output concentration, when modeling both single and multiple odor producing pollutants. In this tip we will discuss further how the correct units can be achieved in AERMOD and ISCST3, as well as how shorter term averaging periods can be calculated for odor concentrations.
The mechanisms of odor dispersion in the atmosphere are the same as the dispersion of other pollutants. When modeling odor concentrations using the U.S. EPA AERMOD or ISCST3 models, there are a few considerations to be made.