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

Figure A‐1 compares the MM5 model estimated wind fields. Figures A‐2 and A‐3 display the
temperature and humidity model performance for the MM5 simulations. As shown in Figure A‐
2, the temperature performance for the three MM5 sensitivity tests using the MRF PBL scheme
(2A, 2B and 2C) is extremely poor using either the 36 or 12 km grid resolution having an
underestimation bias greater than ‐4 degrees that does not meet the temperature bias
performance goal (≤±0.5 degrees).
The wind speed and, especially, the wind direction performance of the MM5 simulations with
no FDDA (1A, 2A and 2F) is noticeably worse than when FDDA is used with the wind direction
bias and error exceeding the performance benchmarks when no FDDA is used. With the
exception of the EXP2H temperature underestimation tendency that barely exceeds the
performance benchmark, the MM5 EXP1C and EXP2H MM5 sensitivity tests that were used in
the CALMET sensitivity tests achieve the model performance benchmarks for wind speed, wind
direction, temperature and humidity.
Tables A‐4 and A‐5 show CALMET estimated winds compared to observations. The “A” series of
CALMET sensitivity tests (RMAX1/RMAX2 =500/1000) tends to have a wind speed
underestimation bias compared to the other RMAX1/RMAX2 settings for most of the base
CALMET settings (Figure A‐1). The “A” and “B” series of CALMET runs tend to have the winds
that closest match observations compared to the “C” (RMAX1/RMAX2 = 10/100) and “D” (no
observations) series of CALMET runs. The use of 12 km CALMET grid resolution appears to
improve the CALMET model performance slightly compared to 80 and 36 km. The CALMET runs
using the MM5 EXP2H 36/12 km data appear to perform better than the ones that used the
MM5 EXP1C 80 km data. CALMET tends to slow down the MM5 wind speeds with the
slowdown increasing going from the “D” to “C” to “B” to “A” series of CALMET configurations
such that the “A” series has a significant wind speed underestimation tendency.
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