Table of Contents - The Atmospheric Studies Group at TRC

Section 9: CALPUFF
table. A description of the contents of the header record is provided in Table 9-10, and the data records
are described in Table 9-11. The header record contains an 80-character title of the data set.
Note that other data associated with the PLMMET.DAT are provided in the CALPUFF.INP control file.
These data include the anemometer height, surface roughness length, land use type, elevation, and leaf
area index of the modeling region. The anemometer height is required in the vertical power law
extrapolation of the wind speed. The roughness length is used to estimate the micrometeorological
variables, the turbulence-based dispersion coefficients (when selected), and in the calculation of dry
deposition velocities. The land use category is used to determine if urban or rural dispersion coefficients
are appropriate when the Pasquill-Gifford/McElroy-Pooler dispersion coefficients are used. Also see the
variables IURB1 and IURB2 in Input Group 12 of the control file. They define the range of land use
categories that are to be considered urban (i.e., if the value of the land use category in the PLMMET.DAT
file is between IURB1 and IURB2, inclusive, the modeling domain will be consider urban). Otherwise, it
will be considered rural. The leaf area index is only used by the model if dry deposition velocities are
being computed. The elevation is used to fill the 2-D terrain elevation array in CALPUFF that is
normally filled from the CALMET file. This array is used to determine, through interpolation, the
elevation of the gridded receptors generated by the model as an option. Because a single value is
available here, all of the gridded receptors will be assigned this elevation. Receptor-specific elevations
are assigned to each discrete receptor by the user in the CALPUFF control file (see Input Group 17).
9-147