Table of Contents - The Atmospheric Studies Group at TRC

Section 9: CALPUFF
available temperature gradient data are used to estimate the inversion strength.
Precipitation data, solar radiation, and relative humidity are not required in CTDMPLUS. They may be
added to SURFACE.DAT in an extended data record. These fields may remain blank if they are not
needed for the CALPUFF options selected. Precipitation is needed for wet deposition modeling, and the
solar radiation and humidity data are needed for chemical transformation calculations.
Other data associated with the SURFACE.DAT and PROFILE.DAT are provided in the CALPUFF.INP
control file. These data include the land use type, elevation, and leaf area index of the modeling region,
and two control variables (ISIGMAV and IMIXCTDM). 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 during convective regimes. 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 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). ISIGMAV indicates the form of the lateral turbulence data,
and IMIXCTDM indicates which mixing height field (observed or calculated) is to be used.
Sample SURFACE.DAT files are shown in Tables 9-12(a-c). Part (a) of the table shows the standard
SURFACE.DAT data record. The extended data record is shown in Part (b) of the table, and the form of
the extended record data with sub-hourly time steps is shown in Part (c). Similarly, sample
PROFILE.DAT files are shown in Table 9-13. Data records for SURFACE.DAT are described in Table
9-14, and data records for PROFILE.DAT are described in Table 9-15. Note that the year may be
specified in either a YY (e.g., 94) or YYYY (e.g., 1994) format. The YY format is the original CTDM
PLUS format.
The PROFILE.DAT file may also be used in conjunction with the other meteorological data options in
CALPUFF to provide measured turbulence data, or to provide the strength of the temperature inversion.
When turbulence data are supplied, wind speeds should be provided in the file as well as the turbulence,
so that conversions between v and can be made.
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