BRAVO Results of CMAQ-MADRID

Betty Pun, Christian Seigneur & Shiang-Yuh Wu

AER, San Ramon

Naresh Kumar

EPRI, Palo Alto

10 October 2002

CMAQ Modeling Domain

CMAQ Simulations

• Two episodes

– 5-15 October 1999

– 10-25 August 1999

• Simulations

– Tracers: completed

– Base PM simulations: completed, revised August simulation in progress

– Emission sensitivity simulations: in progress

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Simulated Values (12 km) Simulated Values (4 km)Observations (6-hr) Observations (12-hr)Observations (24-hr)

October Episode, 4-km and 12-km Simulations, Time Series

Sulfate (g/m3) at Big Bend

October Episode, 4-km and 12 km Simulations, Regression Analysis

y = 0.3872x + 2.1778

R2 = 0.6851

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Sulfate (g/m3) at Big Bend

y = 0.1015x + 2.1709

R2 = 0.1091

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4-km simulation 12-km simulation

y = 0.7185x + 2.8018

R2 = 0.143

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October Episode, 12-km SimulationRegression Analysis

Sulfate (g/m3), 39 Sites

Chemical Composition at Big Bend

Observed

sulfate55.2%

ammonium15.6%

nitrate0.9%

EC1.2%

OC11.9%

others15.2%

Simulated

sulfate53.9%

OC19.5%

others11.5%

EC1.0%

nitrate0.0%

ammonium14.2%

Sulfate on 11 & 12 October

PM2.5 on 11 & 12 October

O3 on 11 & 12 October

August Episode, 4-km SimulationTime Series

Sulfate (g/m3) at Big Bend

Oct 17 18 19 20 21 22 230

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Simulated Values Observations (8-hr)Observations (12-hr) Observations (24-hr)

August Episode, 4-km SimulationRegression Analysis

Sulfate (g/m3) at Big Bend

y = -0.0476x + 7.4337

R2 = 0.004

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CMAQ Performance

• First performance evaluation for a regional PM model with a comprehensive database (daily speciated data with good spatial coverage)

• Performance for October PM simulation is satisfactory, at least for BBNP

• Performance for August PM simulation is not satisfactory; sensitivity to boundary conditions is being investigated using REMSAD results to provide better temporal resolution

Emission Sensitivity Simulations

• 100% reduction in SOx emissions from

– Mexico

– Texas

– Other states

• 50% reduction in NOx, VOC and CO emissions from

– Mexico

– Texas

– Other states

CMAQ Schedule

• Tracer simulation results: Analysis completed in October

• Base PM simulations: August simulation revised by late November, performance evaluation drafted by end of November

• SOx emission sensitivity simulations for October episode completed by late November

• SOx emission sensitivity simulations for August episode completed by mid-January (revised simulation)

• NOx/VOC/CO emission sensitivity simulations completed by January (October episode) and February (August episode)