List Your Top 10 Conclusions from OTAG Air Quality Workgroup Activities

In order to build consensus and prepare a representative summary of results, this is page invites members to list their ‘top 10’ observations, conclusions and recommendations resulting from the OTAG AQA workgroup activities. You may leave some entries empty.


1.
OTAG achieved its number one function, which was to delay sanctions while considering transport.
2.
The technical work was first rate.
3.
In retrospect, to expect consensus on the impact of transport among the states was unrealistic. There is enough ambiguity in the science to support large political divisions of opinion.
4.
The greatest failing was to run the work groups all at the same time for so long. This minimized cross fertalization of ideas.
5.
Remember that all of OTAG's work, especially the technical work, is likely to become part of the "record" (for purposes of judicial review) of EPA's rule making on transport. Save your stuff!
6.
The web work has been wonderful.
7.
The failure of the Policy Group to seriously consider disbenefits and residual nonattainment was disappointing. I think their conclusion should have been that attainment is not feasible and we need to devise an attainable standard.
8.
The integretiy of the people in the process was incredible. If only Congress could be like this.
9.
Best wishes to all, David
10.
Submitted by WOJICK PE DR.DAVID on 7/15/97 RecID: DR.DAVIDWOJICKPE

1.
Top 10 things I wish we had gotten around to/ had time for/ might take up in the future:
1. Emissions Data (a): Historical trends (NOx and VOC) - maybe from EPA Interim Inventory - vs. Changes in measured Ozone NOx, Nitrate Deposition, VOC...
2.
Emissions Data (b): Summer seasonal (base year 1990 or 95) spatial pattern vs ozone (maybe averaged 1991-95). How many moles Ozone per mole of NOx emitted & where...
3.
Emissions Data (c): Hourly Disaggregation (or at least the formulae for) by temperature, traffic pattern, day of week vs. similar patterns in ambient ozone & precursors. (Also, maybe a special focus on time periods near leaf out and senescence - which must do a number on isoprene emissions)...
4.
Diurnal Cycle: of measured ozone and precursors (maybe including ratios to ‘non-reactive CO). Diurnal patterns are so strong, there must be much information in residuals from the norm...
5.
High Elevation sites: (including AIRS, Sears Tower, CASTnet, Canadian) vs. Nearby low elevation sites, maybe with time lags (ie. early AM mountain vs next PM low elev.). In some regions, sufficient sites exist at multiple elevations to explore gradients...
6.
Model vs. Ambient: More detailed focus on (predictions, ambient, met, and emissions) at locations and/or time periods when model performance is worst/best, under/over...

7.
Model Representativeness (a): More detailed evaluation of "episode representativeness" by region, met condition, and alternate ozone metrics. A simple starting question: what fraction of past 10 years "high ozone days" at each site is included by the model periods?

8.
Model Representativeness (b): Identify and evaluate other episode periods (on a sub-regional basis) which are specifically dissimilar to the model episode periods...
9.
Comparisons of Surface Met (NWS stations, etc.) with upper air met (NGM, etc.) vs. ambient ozone. What's relationship between ozone and surface & synoptic scale flows, directions, speeds?

10.
NOx Mass Balance: over OTAG domain or subregions (using NAPAP-like flux estimates, Nitrate wet and dry deposition, etc.). What is the ultimate fate; where does it go?
Submitted by Poirot Richard on 5/17/97 RecID: RichardPoirot1

1.
1. Ozone transport occurs over multiple scales of distance and direction, and on any given day can be predominantly influenced by local (surface) flows, mesoscale (channeled) flows, and/or synoptic-scale (upper level) flows - spanning ranges of a few 10s of miles up to about 500 miles.
2.
2. The perceived contribution of transport is strongly dependent on how the "ozone problem" is defined. Local emissions are more important for peak 1-hour concentrations than for longer averaging times (8-hour, seasonal SUM06) - where larger areas and longer distance scales become increasingly important.
3.
3. With the exception of occasional exceedances at remote locations, transport over more than a few 10s of miles is rarely a "predominant" cause of peak 1-hour violations. Rather, the effect of transport is to increase "background" levels, providing less margin for local source contributions.
4.
4. OTAG is (was?) a geographically well-configured ozone control region, as ozone levels at the periphery of the region are typically close to "natural" tropospheric background levels, and ozone levels within OTAG are lowest with flows from outside the region.
5.
5. OTAG is a politically poorly-configured "voluntary" ozone control region, as it is difficult to justify costs of local controls in areas without current exceedances for perceived benefits in downwind jurisdictions.
6.
6. The relative importance of transport contributions to "ozone problems" is least in Southeastern sections of OTAG, and generally increases in a clockwise direction from SE to SW to NW to NE.
7.
7. For uncertain reasons, the OTAG UAM-V model appears to overpredict ozone levels in the South (where local emissions are most important) and underpredict ozone levels aloft and in the Northeast (where transport contributions are most important).
8.
8. Episodic photochemical grid modeling is a useful tool for the general evaluation of alternative control strategies. However, its usefulness for evaluating specific geographic strategies is limited to the specific meteorological conditions of the modeled episodes - which represent only a small fraction of the conditions which have been (or will be) associated with high ozone concentrations at all receptors.
9.
9. The Midwest is an important ozone source region for receptor areas in all directions. Possible reasons include: its central location, low morning mixing heights and wind speeds, high afternoon mixing heights, high NOx emission rates, elevated release heights, and chronically high ozone concentrations.
10.
10. Ozone is only one of several environmental issues associated with the VOC and NOx emission precursors. Other problems which would benefit from VOC and NOx emission reductions include: toxic organics, acid deposition, eutrophication, fine particles, regional haze and global climate change.
Submitted by Poirot Richard on 5/16/97 RecID: RichardPoirot

1.
All ozone nonattainment areas should be considered ozone problem areas.
2.
Since ozone nonattainment is directly correlated with population density regional planning should be incorporated into any control strategy adopted.
3.
All areas of the OTAG region contribute to ozone transport to some degree.
4.
Due to the uncertainties of the modeling and limitations of the monitoring data, "wiggle room" should be part of any control strategy allowing for corrections along the way. A process of continuous improvement should be adopted that will allow for measurement verification, while allowing for meteorological variability, of control strategy effectiveness.
5.
Historical trends indicate that control strategies already implemented are working. All emissions should be capped, while allowing for uncontrollable meteorological influences, based on historical data to maintain the trend. This is especially true in the nonattainment areas.
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10.
Submitted by West Jeffrey on 5/14/97 RecID: jeffreywest1

1.
In some regions of the OTAG domain, peak ozone concentrations and the number of exceedances have declined dramatically over the last 15 years.
2.
Only a few urban areas exceed the current standard several times per year on average.
3.
Transport of meteorological conditions is not the same as transport of ozone. The spatial correlation of met conditions is greater than the correlation of ozone concentrations.
4.
Ozone transport does occur on a local, sub-regional, and regional scale.
Local ozone transport, 30-150 miles, contributes the most to ozone non-attainment.
Sub-regional ozone transport occurs over a distance of 100-200 miles and includes significant ozone transport in
nocturnal jets. Regional ozone transport can occur up to 200-300 miles.
5.
Scales of transport vary in OTAG domain, with greater transport exhibited in the MW-NE than the SE.
6.
Mixing heights above water bodies are a factor of 10 lower than above the land. This leads a concentrating effect of urban plumes as they leave the coast and subsequent ozone violations if the plumes subsequently come ashore. This effect is seen along Lake Michigan, the LI sound, and the Atlantic coast. This means that lowering coastal ozone in these locations is extremely intractable. Inland concentrations may be much lower due to increase mixing.
7.
The scale of ozone transport is much larger than the scale of precursor transport.
8.
Weekend/weekday effects need to be studied further. Several areas (LMOS and SCAQS I think) have seen their highest ozone peaks on weekends yet Sunday exceedances are fewer than weekdays. The implications for transport times and distances also needs investigating.
9.
The workgroup seems unwilling to focus on the temporal aspect of its charge (trends in time), instead focusing on spatial correlations.
10.
Submitted by Feldman Howard on 5/9/97 RecID: HowardFeldman

1.
Short range ozone transport (<150 miles) appears to be far more important than longer range transport.
2.
While there is evidence of long range transport, its influence appears to be small and is not the controlling factor in the severe nonattainment areas.
3.
Changing the ozone standard will potentially result in many areas currently in attainment becoming nonattainment.
4.
Bringing together a group to look at this issue has been great. Even though we haven't (and probably never will) always agree, the discussions have been a good learning experience for everyone.
5.
The use of the Web site to communicate has been great. Now if we could just get everyone to remember to check it regularly....
6.
The amount of ambient data and analysis we have concentrated here during the past couple of years has been phenomenal.
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10.
Submitted by Long David on 5/9/97 RecID: DavidLong

1.
Ozone transport does occur on a local, sub-regional, and regional scale.
2.
Local ozone transport, 30-150 miles, contributes the most to ozone non-attainment.
3.
Sub-regional ozone transport occurs over a distance of 125-250 miles and includes significant ozone transport in nocturnal jets.
4.
Regional ozone transport can occur across the OTAG region, 200-500 miles, but generally with lower concentrations than sub-regional or local transport.
5.
A majority of the controllable ozone (i.e. above background) found in urban areas is a result of same day emissions.
6.
Regionally transported ozone can contribute approximately 30% of the excess ozone found in urban areas.
7.
Ozone exceedances along the coast of Maine have been shown to be the result of local and sub-regional ozone transport.
8.
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10.
Submitted by West Jeffrey on 5/7/97 RecID: jeffreywest

1.
The OTAG process works. Bring together all of the stake holders and the high degree of interaction between the science and policy groups kept the science largely policy oriented.
2.
The bringing together of multiple analysts into a "community" for sharing of ideas, critical review of results, presentation of multiple points of view, etc. clearly added to the quality of the work done.
3.
The central portion of the OTAG domain is truly unique with respect to ozone and ozone transport. It persistently has elevated ozone levels producing an "ozone pool." Transport in any direction from this region has been implicated with high ozone levels in neighboring areas.
4.
High ozone levels in the southern portion of OTAG are associated with stagnant transport conditions resulting in shorter transport scales than on average.
5.
High ozone levels in the northern portion of OTAG are associated with higher speed and persistent transport condition from inside the OTAG domain.
6.
The change in emissions during the weekend from the that of the weekday successfully reduces the peak ozone concentrations. Now, if we could only determine what these weekend-weekday emission differences are.
7.
The model does surprising well in and around the major urban centers.
8.
There is evidence that the model results are biased high in the southern portion of OTAG and low in the northern portion of OTAG. Why, is the model getting the transport right?
9.
The new standard of 80 - 90 ppb will cause large regions of the Eastern US, such as the Ohio river valley, to become out of attainment. These regions will now need to control local emissions for their own sake, and all of their neighbors will benefit.
10.
OTAG was not the beginning and will not be the end of the issue of ozone and ozone transport. Maintaining the information and communication/collaboration/cooperation infrastructure developed will help greatly in preventing the need for rediscovering many of the whats, hows, and whys discovered and rediscovered in this go around.
Submitted by Schichtel Bret on 5/6/97 RecID: BretSchichtel

1.
The OTAG Process. The science-policy interaction and the stakeholder participations were a breeze of fresh air. Is the command & control approach dead for good? Now I have a clue what the heck ‘policy making’ is and how it differs from 'polticing'.
2.
The Community. A LOT of the past 18 months went into interacting with the AQA WG members and dwelling in our Web habitat. It made the activity both personally fun and professionally rewarding. A real virtual community but remember, we are not alone...!
3.
'Group Intelligence'. The total WG output is MUCH more than the sum of the parts. Learning from each other was clearly visible - a taste of what 'group intelligence' and ‘learning organizations’ could do in the future.
4.
The sharing of data, tools and infrastructures. We have a long ways to go. We got to work on re-using data and tools so that more time is left for critical thinking, evaluation, organization, tennis. The mind of the analysts is a terrible thing to waste on mindeless jobs.
5.
The Web technology & culture. Breathtaking. May YOU also live in interesting times. Without the Web, AQAWG would have been just another stuffy commettee.
6.
The large ‘ozone pool’ in the center of OTAG is quite impressive. Whenever air stagnates over it and then takes off, a mass of ozone hits the downwind areas like an ozone ‘blob’ - wherever it moves, N,S,E,W.
7.
The new 80 (or 90) ppb standard is ‘big’, even if EPA allows 10 exceedances/yr. At 80-90 ppb, the Ohio River Valley becomes another large nonattainment area. The reason I think that’s ‘big’ is that then ORV has to control ozone for it’s own sake, not for the sake of the northeasterners - less no need for fingerpointing..
8.
Observing the weekday-weekend O3 difference was nifty. It shows you how modest emission changes can yield big 120 ppb ‘peak shaving’ reductions.
9.
The ozone transport issue somehow does not grab me as a huge challenge. With a hefty dose of immodesty...we new the gross features of the ozone transport over 20 years ago, e.g. Ozone in Hazy Air Masses, 1976 . Apportioning the ozone between tropospheric(i.e. biogenic), regional and local and a full accounting by state/industry/VOC-NOx is a different matter.
10.
The RAMS/UAM-V model was doing pretty good, considering how little non-urban calibration/verification took place. It was sad that AQAWG could not develop a collaboration with the modelers. Could not get them out of the alphabet-soup of their scenarios. I have the feeling, that now the modelers wish they did...Boy, already 10 items? I just got started! I'm sure you would love to see 2 more pages or ramblings :).
Submitted by Husar Rudolf on 5/1/97 RecID: RudolfHusar

1.
The community of air quality analysts and the analytical networking capabilities that have been created as a result of OTAG have contributed substantially to the understanding of ozone pollution in general and ozone transport specifically. Nonetheless, much remains to be learned. Maintaining this network and its analytical capabilities, possibly in a Phase II of OTAG which performs analyses aimed at fine-tuning policy actions in the future, is highly recommended.
2.
The proposed ozone standard will make ozone transport more critical across entire domain.
3.
Model results, which are episodic in nature and therefore limited in scope, should be interpreted in light of results from air quality analysis results, which are generally climatological and therefore more robust.
4.
Based on visual comparison of air quality data and modeled result patterns, the UAM-V model performs well regionally; however, several analyses suggest it may understate the impacts of ozone transport.
5.
Significant transport of ozone via nocturnal flows aloft has been documented by aircraft measurements. Exact contributions from these flow
6.
The scale of (ozone transport) influence calculated in several air quality analyses tends to be greater than that calculated from modeled results.
7.
The OTAG domain is well-suited as an air quality control region because most of the incoming air carries little ozone; in contrast the OTR is not, because a significant portion of the incoming air carries excess ozone.
8.
Stagnation and shorter-range transport appear to be more significant during ozone episodes in the southern portions of the OTAG domain.
9.
Long-range transport appears to be more significant during ozone episodes in the Midwest and the Northeast; not so much in the South and Southeast.
10.
The central portion of the OTAG domain is implicated most often in transport and high ozone levels.
Submitted by Guinnup David on 4/30/97 RecID: DavidGuinnup


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