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

6.4.1.1 Spatial Analysis of Model Performance
Four spatial analysis model performance statics have been identified and are discussed in this
section: FMS, FAR, POD and TS. Figure 6‐5 displays the FMS spatial analysis performance
metrics for the five LRT models and the ETEX tracer study field experiment. Recall that the FMS
statistic is define as the overlap divided by the union of the predicted and observed tracer
clouds with a perfect model receiving an FMS score of 100%.
60%
50%
40%
30%
20%
10%
0%
Figure of Metric in Space (FMS)
(Perfect = 100%)
CALPUFF SCIPUFF HYSPLIT FLEXPART CAMx
Figure 6‐5. Figure of Merit in Space (FMS) statistical performance metric for the five LRT
models and the ETEX tracer field experiment.
Figure 6‐6 displays the False Alarm Rate (FAR) performance metrics. The FAR metric is defined
by the number of times that a tracer concentration was predicted to occur at a monitor‐time
when no tracer was observed (i.e., a miss) divided by the number of times a tracer was
predicted to occur at a monitor‐time (i.e., sum of misses and hits); a perfect model (i.e., one
that had no misses) would have a FAR score of 0%.
111