Documentation of the Evaluation of CALPUFF and Other Long ...

compact discs, which were used to obtain the hourly surface observations. The surface stations
used for the SRL75 CALMET modeling are shown in Table 4‐2.
Table 4‐2. 1975 Savannah River Laboratory surface meteorological stations.
State Cities
Georgia Athens, Atlanta, Augusta, Macon, Savannah
North Carolina Asheville, Charlotte, Greensboro, Raleigh‐Durham,
Wilmington
South Carolina Charleston, Columbia, Greer‐Spartanburg
Twice daily soundings came from the second set of compact discs, the Radiosonde Data for
North America. The upper‐air rawinsonde meteorological observations used in the SRL75
CALMET modeling are shown in Table 4‐3.
Table 4‐3. 1975 Savannah River Laboratory tracer experiment rawinsonde sites.
State Cities
Georgia Athens, Waycross
North Carolina Greensboro, Cape Hatteras
South Carolina Charleston
Six vertical layers were defined for the CALPUFF modeling to be consistent with the Irwin (1997)
and EPA (1998a) modeling as follows: surface‐20, 20‐50, 50‐100, 100‐500, 500‐2000, and 2000‐
3300 meters.
MM5 prognostic meteorological model simulations were conducted using grid resolutions of
36, 12 and 4 km. The CALMET modeling used the 12 km MM5 data. The MMIF tool was
applied using all three MM5 grid resolutions and using the first 27 MM5 vertical layers from the
surface to approximately 6,500 m AGL.
4.2.2 CALPUFF Control Options
The following CALPUFF control parameters, which are a subset of the control parameters, were
used. These parameters and options were chosen to be consistent with the 1977 INEL study
(Irwin 1997) and 1998 EPA CALPUFF evaluation (EPA, 1998a) studies. Note that use of the slug
option (MSLUG = 1) is fairly non‐standard for LRT modeling. However, that was what was used
in the 1997 INEL and 1998 EPA studies so it was also used in this study’s CALPUFF evaluation
using the SRL75 tracer database.
Technical options (group 2):
MCTADJ = 0 No terrain adjustment
MCTSG = 0 No subgrid scale complex terrain is modeled
MSLUG = 1 Near‐field puffs modeled as elongated (i.e., slugs)
MTRANS = 1 Transitional plume rise is modeled
MTIP = 1 Stack tip downwash is modeled
MSHEAR = 0 Vertical wind shear is NOT modeled above stack top
MSPLIT = 0 No puff splitting
MCHEM = 0 No chemical transformations
MWET = 0 No wet removal processes
MDRY = 0 No dry removal processes
MPARTL = 0 No partial plume penetration
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