Table of Contents - The Atmospheric Studies Group at TRC

Section 9: CALPUFF
values in time provided in Input Group 5. Note that the temporal variation factors are specific to both the
species and the air mass. Input Group 2 names the six species that will be emitted along the boundary of
the computational domain.
Input Group 3 defines the properties of each air-mass that is either constant, or that uses the factored time
variation. In subgroup 3a, each air-mass is given a name and an index, followed by the thickness of the
layer associated with the air-mass, and the concentration of each species. The name is used to identify airmass
properties in subsequent sections of the file, and the index is used to associate each air-mass type
with specific cells along each boundary of the domain. Concentrations are entered in the order defined in
Input Group 2. Here we have used generic names to suggest the characteristics of each air-mass, and
have provided concentrations for each species. This is only intended to illustrate the structure of the
BCON.DAT file, and should not be interpreted as typical values suitable for any application.
Subgroup 3b provides the temporal variation factors for the number of species/air-mass combinations
indicated in Input Group 1 (NSBC). Only SO 2 for each of three air-masses (clean, urban, and model) is
given a temporal variation here.
Input Group 4 assigns the air-mass types to cells along each boundary, using index values assigned in
subgroups 3a and 5a. All cells along the north boundary and the south boundary are assigned to names
NORTH and SOUTH, respectively. The cells along the west and east boundaries are entered in pairs,
assigned to the variable name WEST-EAST. All of these assignments should be oriented to produce a
"map-like" representation of the domain, with north at the top.
Input Group 5 defines any remaining air-mass types with properties that may vary hourly. Subgroup 5a
assigns the air-mass name and index, and subgroup 5b identifies the time-period that is included in the
data records. The input group terminator (!END!) for 5b must be followed immediately by the data
records. The first record of each time period defines the range of hours for which the concentration data
are valid by listing the beginning date(YYYYJJJ) and hour(HH), and the ending date and hour. The hour
is denoted by the time at the end of the hour (00-23 LST).
For example, a 3-hour period would be:
1987056 23 1987057 01
and a 1-hour period would be:
1987056 23 1987056 23
Subsequent records of each time period provide the data for each air-mass. Each record contains the airmass
name (in single quotes), the layer-top (m), and the concentration of each species (units specified by
IBCU).
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