Comments on Final Report, Vol. I: Executive Summary

Comment on Executive Summary, Vol I

each diagram should have a reference.

Submitted by jeffrey west on 6/11/97 RecID: jeffreywest7

Re: Comment on Executive Summary, Vol I

Well, we have not used references in ExesSum...However, on the web version there should be references and links to the supporting reports. Some of us talked about adding 'evidence' pages (with web links) to each of the ExecSum statements as notes and references. [A perfect (summer) task for continuing OTAG the process - to be added to Poirot's 'wish we had gotten around to/ had time for/ might take up in the future' - list].

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar

Comment on Executive Summary, Vol I

Comment on abstract: You might also consider a acknowledgment page to the major group participants.

Submitted by jeffrey west on 6/11/97 RecID: jeffreywest6

Re: Comment on Executive Summary, Vol I

It may be difficult to assemble a Politically Correct set of 'Special Thanks..' to the workgroup members or to anyone/anything else. The co-chair persons were the appointed representatives of the WG to the Policy Group and to the public, so they are named.

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar1

Comment on Executive Summary, Vol I

Comment on abstract: 5th para. additional sentence to be added at end.. "However, data analysis indicates that urban areas are still the major source of unhealthy ozone levels through out the OTAG region."

Submitted by jeffrey west on 6/11/97 RecID: jeffreywest5

Re: Comment on Executive Summary, Vol I

Boy, if that little word THE was'n there..

The wording in the body of ExecSum says:

.. urban nonattainment areas contribute significantly to their own ozone problems as well as to downwind areas within their areas if influence, 150-500 miles away.

How about augmenting the 3rd sentence in para 5:

Urban nonattainment areas contribute significantly to their own ozone problems and VOC controls appear to be effective for urban 'peak shaving'...

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar2

Comment on Executive Summary, Vol I

Comment on abstract: 5th para. 4th sentence should read " Emissions in the central part of the OTAG region....."

Submitted by jeffrey west on 6/11/97 RecID: jeffreywest4

Re: Comment on Executive Summary, Vol I

Fine, lets clean it up, but we have been calling OTAG a domain, not a region, so it will read:

Emissions in the central part of the OTAG domain....

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar3

Comment on Executive Summary, Vol I

Comment on the abstract: 5th para. 3rd sentence delete " urban 'peaking shaving' " and insert "lowering the maximum ozone values found in urban non-attainment areas",

Submitted by jeffrey west on 6/11/97 RecID: jeffreywest3

Re: Comment on Executive Summary, Vol I

I used 'peak shaving' for crispness and brevity of the abstract but it meant to say the same as Jeff's wording. What do you say?

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar4

Comment on Executive Summary, Vol I

Comment on the abstract: 3rd para. 6th sentence should read "(300-500 miles at 60-80ppb)"

Submitted by jeffrey west on 6/10/97 RecID: jeffreywest2

Re: Comment on Executive Summary, Vol I

Jeff, I am not sure what to make of the 'at 50-80 ppb'. The scale of average ozone transport should not depend on concentration. Of course, the scale of peak O3 does and that is the point of the 'perceived range' sentence.

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar5

Comment on Executive Summary, Vol I

Comment on the abstract: 2nd para. 2nd sentence - delete "and along the industrial Ohio River Valley" or insert the words "urbanized and" before industrial,

Submitted by jeffrey west on 6/10/97 RecID: jeffreywest1

Re: Comment on Executive Summary, Vol I

Fair comment, the Ohio River Valley is industrial and urbanized, so the new wording is:

...near major metropolitan areas and along the industrial and urbanized Ohio River Valley.

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar6

Comment on Executive Summary, Vol I

Comment on the abstract: 2nd para. 1st sentence should read "30-50ppb" as agreed at a earlier meeting;

Submitted by jeffrey west on 6/10/97 RecID: jeffreywest

Re: Comment on Executive Summary, Vol I

I have no problem with making the upper end 50 if we also make the lower end 20 and indicate that it is a range. So, it would read:

...range of ozone at the edges of the OTAG domain corresponds to the tropospheric background of 20-50 ppb.

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar7

Re: Re: Comment on Executive Summary, Vol I

I can not think of any justification to lower the range to 20 ppb.

Submitted by jeffrey west on 6/18/97 RecID: jeffreywest8

Comment on Executive Summary, Vol I

Ozone is indeed controllable by measures within the OTAG domain. The high ozone concentrations in excess of the tropospheric background originate from within the OTAG region (Figures 12 and 13); tropospheric background levels of ozone are found at nearly all of the borders of the OTAG domain (Figure 3), with the exception of the Windsor-Quebec corridor. This means that the high ozone concentrations are not due to external influences but contributed by sources internal to the OTAG domain. Furthermore, the high ozone concentration regions roughly coincide with the pattern of anthropogenic precursor emissions as modified by atmospheric dispersion. Consequently, it can be inferred that most of the excess ozone concentrations observed within the domain result from anthropogenic emissions within the domain.

[COMMENT: The data actually indicated that ozone is not controllable in the OTAG domain. See comment above on ozone controllability.]

Submitted by Howard Feldman on 6/10/97 RecID: HowardFeldman11

Re: Comment on Executive Summary, Vol I

The argument is simple: if most of the excess O3 within OTAG is anthropogenic, emitted inside OTAG, then it is controllable, in priciple. Of course, achieving a specific standard is not addressed here.

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar8

Comment on Executive Summary, Vol I

The distances of ozone impact deduced from multiple types of analysis range from 150 to 500 miles. The directly attributable influence of specific urban areas can be traced to some 150-200 miles before the urban-industrial plumes merge indistinguishably into the regional ozone pool. Ozone and precursors transported at night can have a significant impact hundreds of miles downwind the next day.

[COMMENT: This is misleading. As indicated elsewhere in the report, there is transport less than 150 miles which contributes most to ozone non-attainment. The language in the two-pager is much better and should be inserted instead of the above: "Ozone transport does occur in the OTAG domain on local, sub-regional, and regional scales. Local transport, in the 30-150 mile range, likely contributes most to ozone nonattainment. Sub-regional transport occurs over the 100-300 mile range, and regional transport can occur over the 300-500 mile range, often including significant transport via nocturnal jets aloft. In general, the longer the transport distance, the lower the ozone impact."]

Submitted by Howard Feldman on 6/10/97 RecID: HowardFeldman10

Re: Comment on Executive Summary, Vol I

The ozone transport range of 150-500 miles has been on the Workgroup table throughout the past year. The local, sub-regional and regional ranges you are referring to pertain to the different regimes of transport.

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar9

Comment on Executive Summary, Vol I

Strong ventilation with high wind speeds prevents the local build-up near the sources (Figure 6b), but contributes to long-range transport and regional ozone, particularly during directionally persistent wind conditions (Figure 7a).

[COMMENT: I am appalled by Figure 7a's inclusion in this report, "Telling the OTAG Ozone Story with Data." Figure 7a is not based on data but is a fiction and should be deleted from the report. Subsequent Figures 8 show data; note that none of the wind patterns look like Atlanta to the NE transport. The caption to figure 7a notes "the accumulation of ozone over the northeastern quadrant of the domain." Of course, since its only an assumed flow, if you assumed flow from the NE to the SW the accumulation would be there!]

Submitted by Howard Feldman on 6/10/97 RecID: HowardFeldman9

Re: Comment on Executive Summary, Vol I

Our fault - improper figure labeling . Lets call it a case of misread figure captions. However, based on urging from Rich Poirot, Figure 7a was replaced by a chart of average O3 vs. local surface wind speed for different cities. The source is the same Husar-Renard report on the Web.

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar10

Re: Comment on Executive Summary, Vol I

Personally, I find figure 7a to be among the most useful illustrations in the report - especially given objective of conveying an "Executive Summary". While it is "schematic" in nature, and does not represent a specific data-derived snapshot in time, it is most definitely based on data - collected during the (NARSTO-NE) most intensive field measurement program ever conducted in the Northeast (and the only program with sufficient 3 dimensional meteorological data to understand the importance of the 3 different types of meteorological flow regimes which the graphic illustrates). Each of the identified types of flow regimes has on different occasions (and sometimes during a single episode) been identified as representing an important meteorological flow regime contributing to short or longer distance transport associated with high ozone in the OTR. Many similar data-derived trajectories at similar heights were presented during and subsequent to the NARSTO-NE Data Analysis Symposium last Fall. This schematic image itself represents a multi-scientist consensus summary of some of the key NARSTO-NE findings, and has been well-received in various scientific forums. It has also been presented (without adverse comments that I recall) on more than one occasion to the OTAG AQA workgroup, Modeling and Assessment Workgroup and Policy Group, and was posted (with more detailed description) on the OTAG AQA website for review and comment 4 months ago (see http://capita.wustl.edu/OTAG/Reports/Otagrept/Otagrept.html). If there are any objections to the technical validity of the illustration, there are and have been many appropriate forums to voice those concerns.

Submitted by Richard Poirot on 6/11/97 RecID: RichardPoirot

Re: Re: Comment on Executive Summary, Vol I

Wait a minute, maybe Howard & I are commenting on different Figure 7a's or mixed captions? From my web-browsers view the caption for Figure 7a (ozone sorted by SW wind direction, from Husar and Renard analysis) falls directly under Figure 7b (NARSTO-NE flow schematic, from Blumenthal et al.). I too would have been "appalled" if I associated one figure with the other caption. I think both Figures 7a and 7b (and their captions are quite good (and are carefully derived from data), but it needs to be made more clear which caption goes with which figure (note: these are fine in the printed version of the report).

Submitted by Richard Poirot on 6/11/97 RecID: RichardPoirot1

Comment on Executive Summary, Vol I

Ten year trends show that the number of 120 ppb, 1-hr exceedances has declined markedly over the past decade in areas like the northeastern Ozone Transport Region (Figure 5a) and Southern California. The percentage reductions of the and 80 ppb, 8-hr exceedances were less.

[COMMENT: API presented work to the AQA WG by STI which showed the temporal trends and also included an adjustment for meteorology. The trends were more dramatic when considering the met-adjusted values. Others have done similar work. Why is this type of trend omitted from this assessment?? It should be included. Second, the 15-year trend, going back to the era of somewhat reliable data, is more dramatic. Why only present 10 year trends? Figures are available for these as well
which could supplement or replace Figures 5a-b.]

Submitted by Howard Feldman on 6/10/97 RecID: HowardFeldman8

Re: Comment on Executive Summary, Vol I

The excellent OTR trends study Howard presented to the AQA workgroup (but not submitted electronically for posting and review on AQA website?) was the only such trends study reported to AQA (that I recall), and was geographically limited to the OTR by design. The API trend report included a "meteorological" adjustment - which might more precisely be called a "temperature" adjustment (ie take the ratio of high ozone days to high temperature days). Incidentally, we applied similar techniques and got very similar results in the NESCAUM region (see 1992 NESCAUM regional ozone summary). One difficulty we experienced was the need to apply a lower temperature threshold for coastal sites - which often experienced high ozone, but rarely (if ever in some cases) experienced 90 degree temperatures. Various alternative "meteorological" adjustments are scattered throughout the literature (and sometime give alternative answers), but all are strictly empirical (attempt to normalize by one or more meteorological variables by ratio or regression). None, that I'm aware of, attempt to normalize for meteorological flow patterns. 1995 for example was (like 1988) atypically hot in the OTR, but was also characterized by an anomolously low frequency of synoptic flows from the SW, compared to other recent Summers (1989-94). 1988 was characterized by an anomolously high frequency of particularly large regional scale, slow moving, high pressure systems with long duration or recirculation. Temperature alone, or any suite of meteorological variables at individual sites may not capture this "meteorological' effect. Anyway, I think "declined markedly over the past decade in areas like the northeastern Ozone Transport Region" is a fair representation, and that getting into all the various met adjustments and caveats would not add clarity.

Agreed, a 15-year trend might look more dramatic. However, if it did, then the last half (post 1988) of the 15 year trend would appear even flatter. A majority of the other OTAG AQA analyses are based at most on 5 to 10 year data sets - for reasons including mistrust of older data, increase in site densities over time, and changes in emissions and atmospheric chemical composition. Yes, we made substantial progress from 1980 to 1986. Has the rate of progress been sustained from 1990 to 1996? Also, by way of counterpoint, the OTAG region as a whole (or OTAG minus OTR) has not seen the same degree of improvement as OTR. For OTAG as a whole, post 88 trends in 8-hr exceedances are pretty flat (and get even flatter as longer averageing times are considered). This seems an important part of the story: substantial progress in reducing 1 hr peaks - especially where focused controls are applied. Less progress for longer averaging times would seem to support your point about "difficulty in attaining new standards�"

Submitted by Richard Poirot on 6/26/97 RecID: RichardPoirot3

Re: Comment on Executive Summary, Vol I

If there are OTAG-scale O3 trends as (not just sub-regional trends), it would be interesting to see. What do you suggest specifically?

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar11

Comment on Executive Summary, Vol I

During the dirtier, high-ozone days (the 90th percentiles) the urban influence is very pronounced but confined to about one or two hundred miles from major metropolitan areas.

[COMMENT: This appears to indicate that transport from the aggregation of sources that make up the urban area is confined to less than 200 miles. How does this jibe with the longer estimates of transport and not the 300-500 miles previously emphasized. This supports modifying the 300-500 value; see other comments.]

Submitted by Howard Feldman on 6/10/97 RecID: HowardFeldman7

Re: Comment on Executive Summary, Vol I

This is how: ( From What are the implied ranges of ozone transport):
"The directly attributable influence of specific urban areas can be traced to some 150-200 miles before the urban-industrial plumes merge indistinguishably into the regional ozone pool."

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar12

Comment on Executive Summary, Vol I

During the summer ozone season, the OTAG domain is periodically ventilated by air coming from outside the domain where ozone concentrations average about 30-40 ppb, corresponding to typical tropospheric background levels measured in the northern hemisphere (Figure 3). It is reasonable to assume that in the absence of anthropogenic emissions, the average summertime ozone concentration would be about 30-40 ppb throughout the OTAG domain. Thus, with the notable exception of the Canadian border along the Windsor-Quebec corridor, there are no significant external source impacts on the domain, at least on a regional scale. Large sections of the domain experience average daily maximum ozone levels of 60 to 80 ppb, double the tropospheric background. The highest average concentrations are observed near major metropolitan areas and in a large central sub-region of the of OTAG domain along the Ohio River (Figure 3).

[COMMENT: There is no basis for inclusion of 30 ppb. As Table 1 indicates, the seasonal daily maximum ozone levels at the corner, background sites is actually more like 40-50 ppb. Furthermore, there is no basis for assuming that biogenic emissions in the OTAG domain would not change those values. Therefore, this paragraph should be changed to reflect the data and to remove any unfounded speculation.]

Submitted by Howard Feldman on 6/10/97 RecID: HowardFeldman6

Re: Comment on Executive Summary, Vol I

Don't agree with Howard's claim that "There is no basis for inclusion of 30 ppb" in the range of 30-40 ppb
employed to describe average summertime ozone levels in many areas external to the OTAG domain, or in the subsequent inference that "in the absence of anthropogenic emissions, the average summertime ozone concentration would be about 30-40 ppb throughout the OTAG domain". The 30-40 ppb range is just what the data indicate in many areas of OTAG's periphery. The modelers, I believe, assume 40 ppb as a domain boundary condition (for the most extreme episodes). OTAG AQA did not much get into the hypothetical question of what is (was) "natural background" in the domain. Although this question was pondered extensively in the 1991 NAPAP State of Science Documents (See SOS-T Vol. I, Report #7). They suggested an annual average of 20-35 ppb for "natural background" near sea level in the US today, and recommend a range of 30-45 ppb as representative of clean background 7-hour (0900-1599)ozone levels during summer in the US. The most remote sites examined in the NAPAP analyses also tend to have relatively minimal seasonal and diurnal variation.

The daily maximum ozone levels (or 3rd highest 8-hr max) which Howard cites as counter example are quite a different selection from seasonal average (or natural background) values. An ocasional occurrence of a high 1-hr or 8-hr max at a "clean" site does not redefine what "natural background" is/was, but could more logically be taken as an indication that the clean site is occasionally influenced by transport. As NAPAP observed, "it is difficult, if not impossible to determine whether any location on earth is free from human influence". Further, to the extent that transport contributes to occasional high 8-hr levels at rural/remote sites in the US, the high levels at these sites don't prove that an 8-hour standard would be un-attainable - but rather indicates that broader-scale regional control programs are warranted.

Submitted by Richard Poirot on 6/26/97 RecID: RichardPoirot2

Comment on Executive Summary, Vol I

VOC controls appear to be effective for urban 'peak shaving' while NOX emission reductions are likely to be effective for regional ozone reductions.

[COMMENT: I'm not sure which, if any, analyses in the AQ group support this conclusion. If there are none, this should be deleted.]

Submitted by Howard Feldman on 6/10/97 RecID: HowardFeldman5

Re: Comment on Executive Summary, Vol I

Weeday-weekend analysis: Urban area VOC (plus NOX) emission reductions shave urban peaks. Regional O3 formation is NOx limited.

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar13

Re: Re: Comment on Executive Summary, Vol I

I would like to emphasize that a significant portion of the high regional ozone is a result of transported ozone from urban areas thus " peak shaving" benefits both urban and regional ozone and probably is the most effective way of achieving attainment.

Submitted by jeffrey west on 6/18/97 RecID: jeffreywest9

Re: Re: Re: Comment on Executive Summary, Vol I, peak shaving benefits

I agree that transported ozone from urban centers contributes significantly to regional ozone, but "peak shaving" may not reduce the regional ozone. If the rate of formation of ozone is delayed than the urban peak would be reduced, but the total contribution to the regional ozone would be the same.

Submitted by Bret Schichtel on 6/21/97 RecID: BretSchichtel

Comment on Executive Summary, Vol I, what is meant by Ozone within the domain is controllable?

The anthropogenic ozone originates from within the OTAG domain and therefore it is controllable with measures inside the domain. The strong weekly cycle of peak ozone concentrations along with the observed parallel 10-year trends of ambient ozone and precursor emissions in some sub-regions suggests that ozone reductions are feasible.

[COMMENT: The notion that ozone within the domain is "controllable" needs further examination. If the implication of "controllable" is that the standard is attainable, this is quite questionable and should be corrected. The arithmetic mean of the daily max 1-hr concentrations over the ozone season range from 0.035 - 0.053 ppm at the "corner sites" is indicated below: (see table 1 in comment below)

The following are the 8-hr daily maxima which would be used under the proposed ozone standard.

TABLE 2. TOP 3 8-HOUR DAILY MAXIMUM VALUES FOR OTAG BACKGROUND SITES. ALLCONCENTRATIONS ARE IN PPM UNITS

Location AIRS ID Year 1 2 3

Aroostook Co., ME 230038001 1989 0.083 0.076 0.066
(NDDN/CASTNet) 1990 0.083 0.074 0.073
1991 0.087 0.083 0.083
1992 0.090 0.082 0.081
1993 0.070 0.065 0.065
1994 0.078 0.069 0.064

Piscataquis Co., ME 230210002 1994 0.075 0.067 0.062
1995 0.048 0.048 0.048
1996 0.072 0.065 0.064

Calhoun Co., FL 120138001 1989 0.082 0.078 0.077
(NDDN/CASTNet SUMATRA) 1990 0.088 0.078 0.074
1991 0.079 0.075 0.074
1992 0.085 0.079 0.079
1993 0.073 0.071 0.066
1994 0.083 0.077 0.077

Geneva Co., AL 010610001 1994 0.074 0.073 0.070
1995 0.079 0.070 0.070
1996 0.068 0.068 0.067

Leon, Co., FL 120730003 1988 0.084 0.082 0.080
(Tallahassee) 1995 0.085 0.079 0.079
1996 0.082 0.082 0.075

Cameron Co., TX 480610006 1994 0.082 0.076 0.076
(Brownsville) 1995 0.076 0.074 0.072
1996 0.071 0.069 0.067

Steele Co., ND 380910001 1995 0.068 0.065 0.063
1996 0.069 0.064 0.063

Mercer Co., ND 380570102 1989 0.094 0.086 0.085
1990 0.059 0.057 0.057
1991 0.060 0.060 0.058
1992 0.071 0.066 0.065
1993 0.060 0.055 0.054

Note that the background, corner sites actually have recorded third highest 8-hr daily maximum concentrations in the range of 0.048 - 0.085 ppm. Clearly, these sites are indicative of a small cushion below the proposed standard at these sites. Undoubtedly, there will be even less cushion in areas of higher emissions densities. Therefore, the report should more correctly indicate that "Ozone may not be controllable by measures within the OTAG domain, if controllable implies attainment."]

Submitted by Howard Feldman on 6/10/97 RecID: HowardFeldman4

Comments on Executive summary Vol I, modeling results

The [COMMENT: add "OTAG"] modeling results have been evaluated based on the model performance and on the representativeness of the selected modeling periods compared to climatological conditions. The model simulations have captured the large-scale features of each episode. However, there was a tendency to under-predict

([COMMENT: add "by" 10-20 ppb

[COMMENT: Over what period?]) the average regional ozone concentrations in the North and over-predict in the South.

Submitted by Howard Feldman on 6/10/97 RecID: HowardFeldman3

Comment on the average range of ozone transport

The average range of ozone transport distance implied from an array of diverse methods is between 150 and 500 miles. However, the perceived range, depends whether one considers the average concentrations (300-500 miles) or peak concentrations (tens of miles at 120 ppb).

[COMMENT: This is misleading. As indicated elsewhere in the report, there is transport less than 150 miles which contributes most to ozone non-attainment. The language in the two-pager is much better and should be inserted instead of the above:

"Ozone transport does occur in the OTAG domain on local, sub-regional, and regional scales. Local transport, in the 30-150 mile range, likely contributes most to ozone nonattainment. Sub-regional transport occurs over the 100-300 mile range, and regional transport can occur over the 300-500 mile range, often including significant transport via nocturnal jets aloft. In general, the longer the transport distance, the lower the ozone impact."]

Submitted by Howard Feldman on 6/10/97 RecID: HowardFeldman2

Re: Comment on the average range of ozone transport

This is why we have been distinguishing the different scales: Ozone as pollutant mass is transported 150-500 miles from the source of its precursors. But the scale of 120 ppb exceedances around a source is much less because of dilution. OTAG was mainly about the transport of regional ozone into nonattainment areas ?!?.

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar14

Re: Re: Comment on the average range of ozone transport

OTAG was and will be, as soon as the rule making comes out, about attainment. As I understand the cyclic nature of the chemistry, ozone and its precursors can transform back and forth as they go along. Molecule by molecule, second by second. This is not fluid dynamics. Thus I think the very concept of the average range of ozone transport is meaningless.

Submitted by DR.DAVID WOJICK PE on 7/13/97 RecID: DR.DAVIDWOJICKPE

Re: Re: Re: Comment on the average range of ozone transport

Ozone transport time is usually figured as the time between precursor emissions and when the ozone is removed from the atmosphere for good. The transport distance is the distance traveled throughout that time.
The issue of ozone destruction/re-formation is only relevant during the ozone formation phase, where the concept of net formation is used to account for the destruction. However, once the formation stops (by depletion of NOx), ozone behaves pretty much like any other pollutant. Most of O3 life occurs during this chemically semi-active state when physical removal is the main kinetic process.
However, I fully agree that in case of O3, further clarifications are needed, e.g:
(1) the definition of characteristic formation, decay and life times needs to be sharpened
(2) these definitions need to be dicussed and accepted by the scientific and enforcement communities and
(3) EPA/States could (should?) use these agreed upon definitions in the implementation phase.
Would such approach, in your view make the definition of transport distances �meaningful�? Alternative suggestions?

Submitted by Rudolf Husar on 7/15/97 RecID: RudolfHusar16

Comment on wind speed and ozone relationship

The analysis of ozone data along with transport winds shows that low windspeeds, <3m/sec, cause ... [COMMENT: "allow" is a more accurate descriptor. Winds don't cause ozone.]

High winds, >6m/sec reduce the concentrations, but contribute to the long-range
transport of ozone
[ Comment: delete the words "long-range." This is a subjective term which is not defined in the report.]

Submitted by Howard Feldman on 6/10/97 RecID: HowardFeldman1

Re: Comment on wind speed and ozone relationship

Hey this is fun! Lets set up a blue ribbon committee to study if gravity causes apples to fall. I would propose Sir I. Newton to chair it. Of course low wind speeds cause ozone ACCUMULATION. Air Pollution 101 :). Now offense, Howard?

Ditto with �long-range transport�. Twenty years ago it was a well-accepted spatial range of ozone and 'acid rain' transport. Some of us went to and organized symposia on that topic in the 70s. Now we have no clue as to what long range transport means. It is greater then mesoscale (few hundred km) and less then global. Anything between about 500 and 5000 km. Was this professorial enough?

Submitted by Rudolf Husar on 6/13/97 RecID: RudolfHusar15

What are the ozone concentrations at the edge of the OTAG domain?

The analysis of more than 600 monitoring stations data shows that ozone at the edges of the OTAG domain corresponds to the tropospheric background of 30-40 ppb. The highest average concentrations within the domain (60-80 ppb)

[COMMENT: What are these values? Hourly averages? Average of daily maxes? Over the year? Over the season? There is no basis for inclusion of 30 ppb. As Table 1 (below) indicates, the seasonal daily maximum ozone levels at the corner, background sites is actually more like 40-50 ppb. Furthermore, there is no basis for assuming that biogenic emissions in the OTAG domain would not change those values. Therefore, this paragraph should be changed to reflect the data and to remove any unfounded speculation.]

TABLE 1. ARITHMETIC MEAN OF THE DAILY MAXIMUM 1-HOUR AVERAGE CONCENTRATIONS OVER THE OZONE "SEASON" FOR OTAG BACKGROUND SITES. ALL CONCENTRATIONS ARE IN PPM UNITS

Location AIRS ID Year ARITHMETIC MEAN

Aroostook Co., ME 230038001 1989 0.0442
(NDDN/CASTNet) 1990 0.0412
1991 0.0426
1992 0.0413
1993 0.0391
1994 0.0434

Piscataquis Co., ME 230210002 1994 0.0391
1995 0.0430
1996 0.0433

Calhoun Co., FL 120138001 1989 0.0472
(NDDN/CASTNet SUMATRA) 1990 0.0497
1991 0.0453
1992 0.0471
1993 0.0456
1994 0.0446

Geneva Co., AL 010610001 1994 0.0415
1995 0.0477
1996 0.0471

Leon, Co., FL 120730003 1988 0.0483
(Tallahassee) 1995 0.0480
1996 0.0487

Cameron Co., TX 480610006 1994 0.0349
(Brownsville) 1995 0.0389
1996 0.0312

Steele Co., ND 380910001 1995 0.0431
1996 0.0450

Mercer Co., ND 380570102 1989 0.0528
1990 0.0435
1991 0.0459
1992 0.0447
1993 0.0395

Submitted by Howard Feldman on 6/10/97 RecID: HowardFeldman

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