Table of Contents - The Atmospheric Studies Group at TRC

Section 9: CALPUFF
9.4 Buoyant Area Source Emissions File With Arbitrarily Varying Emissions (BAEMARB.DAT)
The BAEMARB.DAT file contains buoyant area source emissions data for sources with detailed,
arbitrarily varying emissions parameters. This file can be generated from the output of the Forest
Service's Emissions Production Model (EPM) using a reformatting and preprocessing program provided
with CALPUFF. In the BAEMARB.DAT file, values for the source parameters and emission rates can be
specified for each time step in the run. Plume rise is computed within the CALPUFF model for each
source using the numerical plume rise algorithm.
BAEMARB.DAT is a free-formatted ASCII data file (see Table 9-20 for an example). Multiple files may
be provided if groups of sources possess very different time-variability. For example, group 1 may
require hourly data records for the entire simulation period, while group 2 may produce emissions for
only a few weeks during the simulation. Using a second file for group 2 is more economical to prepare
because a single data record can be used to prescribe a long period with no (or constant) emissions. Each
such file must cover the entire modeling period, no source may appear in more than one file, and the
species list must be identical among these files.
The data in the BAEMARB.DAT file are independent of the horizontal and vertical grid systems being
used in the model. The horizontal coordinates are specified for a particular map projection and datum,
and CALPUFF converts these coordinates to the map projection and datum used in the modeling grid.
Header records of the BAEMARB.DAT file (see Table 9-21) contain the coordinate definitions, number
of sources, starting and ending time periods of data in the file, the time zone, and a list of the emitted
species and the corresponding molecular weights.
The BAEMARB.DAT file contains two types of data records. A set of time-invariant records (see Table
9-22) are read after the header records. These records specify the time-invariant source names and the
emissions units for each source. The units must be either 'g/m2/s' or 'g/s', no other character strings will
be accepted. Two additional fields are read as real variables, but are not used in the current version of the
model. A set of time-varying data follows (see Table 9-23). The time-varying records contain the
coordinates of four vertices that define the perimeter of the source, effective release height, ground
elevation, temperature, effective vertical velocity, effective radius, initial vertical spread, and an emission
rate for each species. Note that the four vertices must be centered in sequence around the perimeter; all
four "x" coordinates followed by all four "y" coordinates.
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