Generic Guidance and Optimum Model Settings for the CALPUFF ...

LIST OF FIGURES
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Figure 2-1. Figure showing examples of how to choose RMAX1, R1, RMAX2 and R2 values. One value
of RMAX1, RMAX2, R1 and R2 apply to all surface and upper air stations. RMAX1 and
RMAX2 is typically the maximum radius of influence of the surface and upper air station,
respectively. The approximate length (km) of RMAX1 and RMAX2 is shown in the figure as
black solid lines. The blue circles represent approximate values (km) of R1 values
representative of all surface stations. In complex terrain the R1 value is usually smaller than
the RMAX value. The pink circle represents the R2 value of the upper air station for level 2
and aloft...................................................................................................................................13
Figure 3-1. Example showing how to estimate TERRAD. Usually, (ridge (km) to ridge (km) ) / 2, plus
add 1 or 2 km. A typical value for TERRAD in this example would be 10km.....................19
Figure 3-2. Aerial photograph of a typical aluminum plant showing rows of potrooms. ..........................23
Figure 3-3. Shows a cross-section of two adjacent buildings with dimensions defined (Schulman and
Scire, 1980). The GUI screen shot below from CALPRO shows the Line Source Input
section......................................................................................................................................25
Figure 3-4. CALPRO GUI screenshot showing the CALPUFF user input control screen for entering line
source data...............................................................................................................................25
Figure 3-5 GUI screenshot from CALPRO showing the CALPUFF user input control screen for the
average properties for line sources.......................................................................................... 26
Figure 3-6 Figure shows the difference between point source plume rise and line source plume rise
(Scire and Schulman, 1981). If you treat a line source as a set of too few point sources you
can seriously under or overpredict the plume rise...................................................................27
Figure 3-7 Comparison of AERMOD and CALPUFF predictions of line source impacts from the
Arkadelphia Arkansas SF6 tracer study compared to BLP predictions. This study shows the
impacts of the line sources alone.............................................................................................28
Figure 3-8. Predictions of 1-hour average SO2 concentrations at the downwind Alcoa Tennessee monitor
for 1977 versus Observations and models, CALPUFF, BLP and AERMOD. The BLP results
based on Version 1.1 of the model as well as the current version of BLP on the U.S. EPA web
site (with modifications to the meteorological file to allow it to run) are shown. CALPUFF
closely matches BLP results while AERMOD significantly overpredicts the observed
concentration measurements. ..................................................................................................29
Figure 3-9 CALPUFF peak, 1-hr average concentration map using 1 hour meteorological data and
default calm threshold of 0.5 m/s. Computed turbulence parameters were used assuming the
default minimum σv of 0.5 m/s................................................................................................33
Figure 3-10 CALPUFF peak, 1-hr average concentration map using 10-minute meteorological data and
default calm threshold of 0.5 m/s. Real turbulence parameters were used with a minimum σv
of 0.2 m/s, σw was left unchanged at the model’s default values. ...........................................34
Figure 3-12 CALPUFF computed σv using model defaults and one hour meteorology. (It is always
preferable to use real measured values of real time turbulence wherever possible)................39
Figure 3-13. Real 10-minute measured σv. (CALPUFF can read this real time data directly). ................39
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