Table of Contents - The Atmospheric Studies Group at TRC

Section 9: CALPUFF
9.11 Site-Specific Turbulence Data (PROFILE.DAT)
CALPUFF provides several options for computing the dispersion coefficients, y and z . In Input Group
2 of the control file, the user specifies a value for the dispersion method flag, MDISP:
1 = dispersion coefficients computed from values of v and w read from a data file
(PROFILE.DAT),
2 = dispersion coefficients determined from internally computed values of v and w based
on similarity scaling relationships,
3 = PG coefficients (computed using the ISCST multi-segment approximation) used for rural
areas and MP coefficients used in urban areas,
4 = same as 3 except that the PG coefficients are computed using the MESOPUFF II
equations.
5 = CTDMPLUS dispersion coefficients computed from v and w for neutral/stable.
If Option 1 or Option 5 is selected, the user must prepare a data file with hourly values of v and w . This
option is intended primarily for application to a single source or facility with onsite measurements of v
and w . Therefore, only one set of observations are allowed in the data base and they are assumed to
apply over the entire computational region.
The CTDMPLUS meteorological data file PROFILE provides for measurements of turbulence as well as
wind speed, wind direction, and temperature at one or more heights on a tower. Because the
PROFILE.DAT file is one of the meteorological formats accepted by CALPUFF, it may also be used for
entering turbulence measurements for use with any of the other options. Its structure is documented in
Section 9.2.4.
9-221