Air emissions modeling is the process of preparing emission inventories for use in air quality models.  Air quality models typically require hourly, gridded emissions of specific pollutants.  This site provides data files needed to support air emissions modeling.  Emissions modeling software is used to prepare emissions inventories for air quality modeling through temporal allocation, spatial allocation and speciation. Temporal allocation produces hourly emissions using temporal profiles. Spatial allocation produces gridded emissions using spatial surrogates. Speciation prepares emissions for the needed pollutants using speciation profiles.

An emissions modeling platform is the full set of emissions inventories, other data files, software tools, and scripts that process the emissions into the form needed for air quality modeling. Each emissions modeling platforms supports air quality modeling of an historic year and one or more later years.  Each platform relies on a version of the National Emissions Inventory (NEI) for most of its data, although some adjustments are made to support air quality modeling.  All data and scripts needed to prepare emissions for air quality modeling are provided with each emissions modeling platform.