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

sigma v (CALPUFF calculated)
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).
sigma v (from sigma theta - measured)
2.5
2
1.5
1
0.5
3.0
2.5
2.0
1.5
1.0
0.5
3
1 hr calpuff sigma v
0
0.0 1.0 2.0 3.0
scalar wind speed (m/s)
4.0 5.0 6.0
10 minute sigma v
0.0
0.0 1.0 2.0 3.0 4.0 5.0 6.0
scalar wind speed (m/s)
Figure 3-13. Real 10-minute measured σv. (CALPUFF can read this real time data directly).
3.6.2 User Options for treating Calms
- Sub-hourly meteorological and emissions data
– Model has a default minimum calm wind speed threshold, of 0.5 m/s, below which
model switches from distance dependent to time dependent sigmas.
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