(BRAVO) Study: Final Report. - Desert Research Institute

Final Report — September 2004
Table 9-7. Model performance statistics for the Monte Carlo simulation of tracer concentrations
averaged over the Big Bend sites (San Vicente, K-bar and Persimmon Gap) and over all six-hour
tracer sites (San Vicente, K-bar, Persimmon Gap, Marathon, Fort Stockton and Monahans Sandhills)
for the entire 4-month study period. Concentrations are in parts per quadrillion (ppq).
MM5 Wind Fields -- Big Bend Sites (K-bar, Persimmon Gap, San Vicente)
Average
Bias
Standard Dev.
RMS
Regression Line
Obs Model Mod/Obs Obs Model Error r 2 Intercept Slope
Eagle Pass 0.219 0.207 0.95 0.28 0.29 0.29 0.18 0.13 0.43
San Antonio 0.430 0.542 1.26 0.79 1.12 1.09 0.14 0.28 0.27
Houston 0.052 0.024 0.45 0.08 0.05 0.07 0.20 0.03 0.75
MM5 Wind Fields -- 6-hour Tracer Sites
Average
Bias
Standard Dev.
RMS
Regression Line
Obs Model Mod/Obs Obs Model Error r 2 Intercept Slope
Eagle Pass 0.344 0.247 0.72 0.29 0.19 0.26 0..31 0.13 0.85
San Antonio 0.418 0.534 1.28 0.67 1.01 0.94 0..18 0.27 0.28
Houston 0.058 0.022 0.38 0.06 0.04 0.06 0.31 0.04 0.81
EDAS/FNL Wind Fields -- Big Bend Sites (K-bar, Persimmon Gap, San Vicente)
Average
Bias
Standard Dev.
RMS
Regression Line
Obs Model Mod/Obs Obs Model Error r 2 Intercept Slope
Eagle Pass 0.219 0.103 0.47 0.28 0.26 0.30 0.23 0.17 0.51
San Antonio 0.430 0.368 0.86 0.79 0.82 0.63 0.48 0.19 0.66
Houston 0.052 0.022 0.43 0.08 0.05 0.07 0.23 0.03 0.80
EDAS/FNL Wind Fields -- 6-hour Tracer Sites
Average
Bias
Standard Dev.
RMS
Regression Line
Obs Model Mod/Obs Obs Model Error r 2 Intercept Slope
Eagle Pass 0.344 0.166 0.48 0.29 0.26 0.34 0.21 0.26 0.51
San Antonio 0.418 0.340 0.81 0.67 0.71 0.55 0.46 0.20 0.63
Houston 0.058 0.020 0.34 0.06 0.04 0.07 0.26 0.04 0.74
The tracer release sites at San Antonio and Houston are farther from Big Bend than
Eagle Pass, approximately 450 km and 750 km distant respectively. Therefore, comparisons
with those tracers test the Monte Carlo model’s ability to simulate more regional scale
transport. As was shown in Figure 9-8, tracer from San Antonio impacted Big Bend and
southwest Texas several times in the first half of October and simulated tracer impacts also
occurred during this time period. The tracer from Houston also had the largest impacts at
Big Bend and southwest Texas in the first half of October.
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