Comments on the OTAG Air Quality Analysis Workgroup Results Summary

Is ozone transported or its precursors?

Is ozone transported, or its precursors? If it is only its precursors, what implications would this have conisdering possible long range transport of NOx? Would reduction of NOx increase ozone in most cities?

If ozone had a lifetime more than one hour in the surface layer, ozone concentration would not decrease at the same rate as temperature(and NO) decreases. This is not observed. Ozone increases with temperature(temperature determines NO emission from bacteria in soil) and decreases with temperature.
Therefore,it appearsthat ozone is not a key factor in thet ransport mechanism, but the precursors are.

For example, typical data below:
Sample Data: Courtesy National Park Service for Badlands, July 25,1989 by hour starting at 1:00 A.M.

Ozone(ppb) Temperature(degree F)
53 74
54 73
53 73
51 71
50 70
49 72
48 75
50 79
53 83
58 88
65 91
67 93
68 94
69 96
69 96
70 96
71 96
70 94
67 91
62 86
60 84
58 81
57 79
54 77



Submitted by John Dege on 5/19/97 RecID: JohnDege

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comments on results summary and ES

comments on volume I ES and the results summary

1. "Trends" have been specifically identified in the tasks yet all trends information has been
omitted. Trends indicate dramatic improvement in 1-hr peak ozone in at least some regions of
the OTAG domain.

2. "highest values in large urban areas" should be "downwind".

3. In the paragraph re distance and direction of transport, the end of the sentence should read
"not clear to what extent this actually represents transport of ozone and/or precursors or is a
meteorological correlation."

4.In that same par please add something to the effect of " Met correlations have been shown to
have a greater geographic extent than ozone concentrations." This is from ST Rao's work.

5. I'm not sure what makes the OTAG domain a well-defined aq control region besides knowing
the name of the states involved. It may actually represent several aq control regions, i.e. south
vs. north.

6. Most of the excess ozone in the OTAG region is attributed to anthropogenic emissions. the
role of biogenics as a VOC precursor was presented and discussed in several efforts. Even if
the OTAG inventory overstates the emissions of biogenics, they still contribute considerably to
the precursors.

7. the sentence containing "...the center of the OTAG domain tends to impact on downwind
areas..." should be deleted. Would we expect them to impact upwind areas?

8.In the last sentence of the ES, drop the clause "such as that being undertaken through the
OTAG process". There is no evidence that the OTAG process has or will develop and commit to
continuous and measurable progress.

Submitted by Howard Feldman on 5/9/97 RecID: HowardFeldman

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