Final Report for the

OTAG Air Quality Analysis Workgroup




The Air Quality Analysis (AQA) workgroup of OTAG has been formed to develop analyses based on air quality data which can be used to independently check or complement analytical results developed through OTAG emission-based modeling efforts. Specifically, the workgroup's purpose statement reads:


  • The Air Quality Analysis workgroup shall identify, characterize, compare, and assess observational data and studies including but not limited to air quality trends analysis, overflight data, and meteorological studies for the purpose of evaluating the effects of the transport of ozone and its precursors on ozone nonattainment in the eastern United States.
  • The activities undertaken by this group have included reviewing existing air quality studies and analyses, developing analyses and visualizations of air quality and meteorological data to help in the understanding of ozone transport, comparing modeling results against available air quality data, and integrating air quality analyses and modeled results into conceptual interpretations of ozone transport for use in policy development. It should be noted that comprehensive model evaluation was performed by the modeling group; the AQA efforts in this area complemented this work.


    The workgroup process has entailed the development and presentation of individual work products in front of the entire workgroup, followed by open review of work efforts and results by the group. This process has been greatly facilitated by the early development of an interactive Internet website which has been used to communicate datasets, analytical tools, results, interpretations, and critical feedback. In addition, policy-relevant summaries and interpretations have been developed and subjected to group reviews in developing this final report.


    In the paragraphs below, the major policy-relevant results, conclusions and recommendations from the AQA workgroup are presented. The conclusions fall into the following major categories:


    Origins and patterns of ozone in the OTAG domain

    Ozone transport in the OTAG domain

    Comparison of episodes with climatological data

    Air quality management implications of analytical results

    Recommendations to Foster Future Analyses

    In this summary, each category includes policy-relevant questions which are answered with brief statements of pertinent analytical results. Technical expositions of the individual analyses and their integration are contained in the supporting documentation for this Executive Summary (Volumes II and III).


    In general, these results provide the background assessment of the current ozone problem necessary place the modeling results in the appropriate context. That is to say, they "set the stage" for the useful interpretation of the modeling of future-year control strategies. As mentioned above, it is important that these analyses be considered as a complement to the modeling results; because their strength lies in the fact that they are based primarily on actual measurements, and in many cases they demonstrate independent corroboration of many of the lessons learned from modeling. They also provide more of a "climatological" view of the ozone problem, which extends beyond the modeled episode days and provides a broader perspective of the ozone problem and its characteristics. Once one has developed an understanding of this broad perspective, the modeling results can be used to subsequently provide a more focused view of individual episodes and control strategy impacts.


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