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Results of URM Runs with Updated Stack Parameters and Corrected Secondary Organic Aerosols. Talat Odman, James Boylan, James Wilkinson, Ted Russell. Outline. URM Modeling Run for the July 1995 Episode with Updated Stack Parameters and Corrected Secondary Organic Aerosols
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Results of URM Runs with Updated Stack Parameters and Corrected Secondary Organic Aerosols Talat Odman, James Boylan, James Wilkinson, Ted Russell Georgia Institute of Technology
Outline • URM Modeling Run for the July 1995 Episode with Updated Stack Parameters and Corrected Secondary Organic Aerosols • Updated Results vs. Old Results • Performance Evaluation • URM Model Results for the July 2010 Episode • 1995 vs. 2010 OTW • Status of Other SAMI Episodes • Conclusions Georgia Institute of Technology
Updated July 1995 Episode • Corrected Stack Parameters in Emission Files • Most changes in Tennessee and Kentucky • Corrected Organic Aerosols • Secondary Formation was not properly treated • Changes in organic aerosols, PM2.5, and PM10 Georgia Institute of Technology
Maximum Ozone on July 11, 1995 Georgia Institute of Technology
Maximum Ozone on July 13, 1995 Georgia Institute of Technology
Maximum Ozone on July 15, 1995 Georgia Institute of Technology
Maximum Ozone on July 18, 1995 Georgia Institute of Technology
Ozone Performance Georgia Institute of Technology
Fine Sulfate on July 12, 1995 Georgia Institute of Technology
Fine Sulfate on July 15, 1995 Georgia Institute of Technology
Fine Nitrate on July 12, 1995 Georgia Institute of Technology
Fine Nitrate on July 15, 1995 Georgia Institute of Technology
Fine Organics on July 15, 1995 Georgia Institute of Technology
Fine Sulfate Performance Georgia Institute of Technology
Fine Nitrate Performance Georgia Institute of Technology
Fine Ammonium Performance Georgia Institute of Technology
Fine Organics Performance Georgia Institute of Technology
Fine Elemental Carbon Performance Georgia Institute of Technology
Fine Soils Performance Georgia Institute of Technology
PM 2.5 Performance Georgia Institute of Technology
PM 10 Performance Georgia Institute of Technology
Coarse PM Performance Georgia Institute of Technology
Fine Sulfate Georgia Institute of Technology
Fine Organics Georgia Institute of Technology
PM 2.5 Georgia Institute of Technology
PM 10 Georgia Institute of Technology
July 2010 Episode • NOx emissions decreased by 39% • NO and NO2 initial conditions decreased by 39% • SO2 emissions decreased by 32% • SO2, SO4, and NH4 initial conditions decreased by 32% Georgia Institute of Technology
Daily Maximum Ozone on July 15 Georgia Institute of Technology
Daily Average Sulfate on July 15 Georgia Institute of Technology
Daily Average Nitrate on July 15 Georgia Institute of Technology
Daily Average PM 2.5 on July 15 Georgia Institute of Technology
Ozone at GSM Georgia Institute of Technology
Ozone at Shenandoah Georgia Institute of Technology
Status of SAMI Runs Georgia Institute of Technology
Conclusions • The corrections to the stack parameters do not show a significant impact on GSM or SHEN. • The corrections to the stack parameters can have a significant impacts on some areas of the Appalachian Mountains (KY, TN, VA, AL). • The correction to the secondary organic aerosols makes a significant impact everywhere in the domain. • Improved model performance for organics, PM2.5, and PM10. • Sulfate and ozone decreased in July 2010. However, nitrate has increased. Georgia Institute of Technology
The Effect of Cations on the Heterogeneous Sulfate Production Georgia Institute of Technology
Introduction • Wet deposition modeling results show ammonium, calcium, and magnesium mass fluxes to be higher than observed and hydrogen mass fluxes to be lower than observed. • S(IV) ==> S(VI) Heterogeneous Pathways • SO2 + H2O2 ==> sulfate • dominant at pH < 5.5 • SO2 + O3 ==> sulfate • dominant at pH > 5.5 • pH = - log[H] Georgia Institute of Technology
July ‘95 Episode Georgia Institute of Technology
May ‘95 Episode Georgia Institute of Technology
May ‘93 Episode Georgia Institute of Technology
February ‘94 Episode Georgia Institute of Technology
March ‘93 Episode Georgia Institute of Technology
Cation Contributions to Acidity • When representing acidity-related measurements, mass concentrations (g/L) are converted to units of equivalents per liters (eq/L) • meq/L = [mg/L] * valence /MW • NH4 (meq/L) = [NH4]/18 • H (meq/L) = [H] • Ca (meq/L) = [Ca]*2/40 • Mg (meq/L) = [Mg]*2/24 Georgia Institute of Technology
July ‘95 Episode Georgia Institute of Technology
May ‘95 Episode Georgia Institute of Technology