CALPUFF and Postprocessors

G.6 CALPOST Input Files
G.6.1 User Control File (CALPOST.INP)
User-specified inputs to CALPOST are read from a control file whose default name is CALPOST.INP. A
description of each input variable is shown in Table G-21, and a sample input file is presented in Table G-
22. This control file uses the same self-documenting control file format as CALPUFF. See Section F.1
for a description of the control file input conventions. Selections may be made by either editing an
existing control file, or by using the CALPOST GUI. Note that you can generate a Anew@ control file
with all of the standard options and comments by saving the ANEW.INP@ file from the GUI to disk.
G.6.2 CALPUFF Output Files (MODEL.DAT and VISB.DAT)
The program reads the concentration/deposition flux data from an unformatted data file (default name:
MODEL.DAT) that is generated by the CALPUFF model (or CALGRID). CALPUFF also generates a
file containing relative humidity data (default name: VISB.DAT), which is read by CALPOST if needed
for the visibility option selected. The structure of these files is described in Section F-13.
G.6.3 Background Concentrations/Deposition Fluxes (BACK.DAT)
As an option, a spatially uniform, hourly background concentration/deposition flux can be added to
modeled concentrations/deposition fluxes before averages are processed in CALPOST. These values are
provided in a formatted ASCII file (default name: BACK.DAT) prepared by the user. Table G-23 lists
the record structure for this file, and a partial listing of a sample file is presented in Table G-24.
Units for the background values may be different from those requested from CALPOST. Therefore, the
scaling factor placed in the header record is an important feature. It converts the native units for the
background concentrations to g/m 3 , or it converts the native units for background deposition fluxes to
g/m 2 /s. These are the internal units used in the CALPUFF output file. Any units conversion specified in
the control file (parameter IPRTU) can then be applied uniformly to both the CALPUFF and background
values. Note that the multiplicative and additive scaling factors (A, B) are not applied to the background
values.
G.6.4 Visibility Measurements (VSRN.DAT)
CALPOST allows the use of visibility measurements to establish hourly background extinction for use in
assessing the change in visibility resulting from modeled emissions. Two formats are supported for these
data, and both are taken from the data files available on CD-ROM from the Interagency Monitoring of
Protected Visual Environments (IMPROVE) program. When background extinction method number 4 is
selected in the control file (MVISBK = 4), transmissometer measurements must be provided in the
MAR 2006 -- PostProc
G-60