MINUTES

Attendees:

John Jansen, Niki Nicholas, Anita Rose, Chris Howard, Eldewins Haynes, Jim Renfro, Brenda Johnson, Talat Odman, Paul Muller, Cindy Huber, Steve Mueller, Bob Imhoff, Jake Gilmer, Sharon Fahrer, Pat Brewer

1) The subcommittees reviewed the assessment schedule and the product delivery requirements necessary to complete the assessment by June 2001. The rate-limiting step is developing emissions strategies for the acid deposition and ozone effects modeling. By January 1, 2001, each strategy must be run for 9 episodes and the results must be integrated to define annual acid deposition and hourly and seasonal ozone inputs for the effects. Paul Muller agreed to summarize questions for the Policy Committee or Operations Committee and the Technical Committee recommendations at the August 8 meeting.

2) Questions from the Technical Committee for the Policy and/or Operations Committees:

a) What are the objectives for information presented at the Governors’ Summit in fall 2001? (Integrated Assessment results only or policy recommendations for state responses based on assessment results?)

b) How does the Policy Committee intend to use geographic sensitivity results? (To design additional strategies or to understand state-specific contributions to air quality that could be used in policy recommendations? If the latter, the current design is not sufficient to understand state-specific contributions.)

c) Given limited time, which strategies and which years are the highest priority? Given limited time to run strategies does the Policy Committee need to see both On the Books and On the Way strategy results? Could one be selected as the “baseline” or “reference case”? Could less than all three Bold, Bold with Constraints, and Bolder strategies be modeled?

d) Does the Policy Committee intend to ask that Incentives strategy be run through the atmospheric model?

e) Does Policy Committee still see value in looking at “proof of concept” strategies based on results of currently defined strategies? How would “proof of concept” strategies differ from current strategies?

f) How does Policy Committee intend to use 2040 air quality modeling results? (Technical Committee will use 2040 results to interpret air quality trends between 2010 and 2040 for acid deposition and ozone effects models.)

3) The Technical Committee would like to recommend that atmospheric model runs be prioritized in three categories:

a) Fall 2000: strategy runs intended to define inputs for acid deposition and ozone effects models. Given time constraints, model On the Way, not On the Books. Model 1 or 2, but not all 3 of the Bold, Bold with Constraints, Bolder strategies. Limit 2040 runs to On the Way and one of the 3 Bold strategies.

b) Winter 2001: sensitivity of atmospheric model results to change in emissions in specific geographic sectors. Georgia Tech will have geographic sensitivity results for SO2 and NH4 for 2010 On the Way by end of August. Delay all other geographic sensitivity results until strategy runs are completed and consider whether different design is needed to provide state-specific results. Current budget may not be sufficient to significantly redesign the geographic analyses.

c) Spring 2001: if desired by Policy Committee, design proof-of-concept strategies, based on initial strategy results, to be run through emissions inventory, atmospheric model, and effects models. Runs through effects models requested after Jan 2001 are not in the current budget.

4) Talat Odman, Georgia Tech, presented model results for the latest changes to emissions for July 95 and July 2010 On the Way. In addition to correcting stack parameters in these runs, Georgia Tech also corrected the chemical reactions for organic aerosols. The resulting changes in ozone and sulfate were generally most obvious in the areas where the stack parameters were changed (TN, KY, WV, AL) and were relatively small in the Smokies and Shenandoah. URM had been under-predicting organic aerosols; the latest changes in URM have greatly improved model performance for organic aerosols. See results on Georgia Tech website (https://mesl.ce.gatech.edu/). Georgia Tech is now rerunning the base case for all episodes and running 2010 On the Way strategy for all episodes. Georgia Tech is also running SO2 and NH3 sensitivities for 2010 On the Way for all episodes. The Modeling Subcommittee will review these results at the August 17 meeting in Atlanta.

5) Bob Imhoff, TVA, presented model results for the first of three episodes, August 1993. Model performance was comparable to that reported by Georgia Tech. TVA intends to complete base case modeling for the remaining two episodes in August and present available results at August 17 meeting in Atlanta.

6) Bob Imhoff raised questions about the potential impact of over-predicting pH in wet deposition. Talat illustrated that the over-prediction was largest for the Mar 93 episode, less for other episodes. In Mar 93 over-prediction of NH4 is responsible for high pH for wet deposition; Ca and Mg levels are comparable to NADP observations. The over-prediction was most notable in the Mar 93 (Tech) and Aug 93 (TVA) episodes. Sulfate formation in clouds is affected by pH, with the hydrogen peroxide (H2O2) pathway dominating in acidic clouds and ozone dominating in more neutral clouds. Talat concluded that even with over-prediction of pH, at least for the Mar 93 episodes, the model is still following the hydrogen peroxide pathway and sulfate production is reliable.

7) The subcommittees reviewed the draft visibility request for proposals and considered options for a technical design workshop. The conclusion is to host a technical design workshop with invited attendants from stakeholder organizations. Individuals that participate in the workshop would not be eligible to respond to the request for proposals. A letter will be sent to workshop participants outlining SAMI’s objectives, atmospheric model design and expected products, and outstanding technical design questions. The technical design will be resolved through the workshop and following the workshop, a request for proposals will be released. Staff was asked to send a pre-announcement of the request for proposals. The request for proposals will be revised to focus on a single objective to use SAMI atmospheric modeling to evaluate visibility responses to SAMI strategies. Please hold August 22-24 (it will be 2 of those 3 days) for the technical design workshop; we are still trying to accommodate schedules.

8) The next meeting is the Atmospheric Modeling subcommittee on August 17, 8:30-4:00 pm in Atlanta, in the 12 floor conference room of the Federal Building. A block of rooms has been reserved at the Wynham Garden Hotel near Perimeter Mall in northeast Atlanta. Call 404/252-3344 to reserve rooms by August 6, 2000.