Area
Source Model
Purpose
The Area Source Model provides the user with a system for preparing area
source, criteria emissions for speciation (lumped-model or discrete speciation)
and reformatting for input to an air quality model. As with the Point Source
Model, the Area Source Model does not compute emissions estimates from
fundamental emissions data. The Area Source Model reduces annual, county-wide
emissions estimates to emissions on an hourly, grid cell-by-grid cell basis.
Main Input
The Area Source Model starts from a foundation emissions data base, updates
the estimates with day-specific estimates, spatially allocates the emissions
into the emissions modeling grid structure, and temporally allocates the
criteria emissions.
Most of the Area Source Model is written in the SAS®
programming language. The area source spatial surrogates allocation component
of the Area Source Model is written in the ARCTM
Macro Language (AMLTM). The primary inputs
to the Area Source Model are the foundation emissions estimates and day-specific
emissions estimates. The primary output of the Area Source Model is the
spatially allocated, temporally resolved, criteria emissions estimates.
Model Flow Chart
Area Source Model Flow Chart is a figure which
shows the execution order of each processor and a description of each processor
that is contained in the Area Source Model. Each area separated by dotted
line represents one specific processing module and the name of each module
is shown at the alternative text area down on the bottom of the page. Simply
click the area, and it will go to this processing module page which includes
a detailed description of each data set and processor. Users should print
this flow chart in Landscape, if they want to use for further
reference.