WRAP Modeling Forum, San Diego Preliminary CAMx assessment of oil and gas emissions on ozone in the Four Corners region Mike Barna1 and Marco Rodriguez2 1Air Resources Division, National Park Service Fort Collins, CO 2Co-operative Institute for Research in the Atmosphere, CSU WRAP Modeling Forum, San Diego 3 November 2006 National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Introduction CAMx runs at NPS-CIRA 2002 annual simulations (36 km) emissions, meteorology from WRAP-RMC evaluate oil & gas impacts, N deposition 2006 RoMANS simulations (36/12/4 km) RoMANS: Rocky Mountain Atmospheric Nitrogen and Sulfur Study Source apportionment to estimate contributions to N and S deposition at Rocky Mountain NP Update RMC 2002 inventory to 2006: mobile, point, NH3, fire National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Introduction Significant increases in NOx and VOC for oil and gas development in WRAP region largest emission increases in NM, CO, UT, WY To evaluate contribution to regional air pollution (e.g., ozone and fine nitrate PM) from O&G, consider two CAMx simulations base emissions base emissions minus O&G run SMOKE’s MRGGRID to combine all base02 emission categories except O&G National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Introduction The difference between these two runs represents the impact of O&G emissions on regional air pollution Results reflect an ‘emissions sensitivity test’, not a true source apportionment (could use CAMx’s OSAT for that) National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Emissions from oil and gas in WRAP region NOx VOC Oil and gas emissions within WRAP: NOx: 125,000 tons/yr (3% of total) VOC: 363,000 tons/yr (2% of total) National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Ozone error and bias for all WRAP fractional error fractional bias National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Ozone performance stats for all WRAP LINEAR REGRESSION Pred = A + B * Obs A = 0.0247769 B = 0.396364 R^2 = 0.251872 MEAN AND GLOBAL STATISTICS Mean Estimation: 0.0414590 Mean Observation: 0.0420879 Standard Deviation of Estimation: 0.0130819 Standard Deviation of Observations: 0.0165641 DIFFERENCE STATISTICS Mean Bias Error: -0.000628896 Mean Normalized Bias Error: 30.9135 Mean Absolute Gross Error: 0.0116230 Mean Absolute Normalized Gross Error: 54.7857 Standard Deviation of Residual Distribution: 0.0150998 Fractional Gross Error: 0.324408 Fractional Bias: 0.0338645 National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

NO3 error and bias for all WRAP fractional error fractional bias National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Example summertime ozone, 6 August 2002 Mesa Verde NP: 65 ppb max hourly concentration National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Ozone at Mesa Verde fractional error fractional bias National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Ozone performance stats for Mesa Verde LINEAR REGRESSION Pred = A + B * Obs A = 0.00854282 B = 0.815839 R^2 = 0.436083 MEAN AND GLOBAL STATISTICS Mean Estimation: 0.0457161 Mean Observation: 0.0455645 Standard Deviation of Estimation: 0.0127932 Standard Deviation of Observations: 0.0103552 DIFFERENCE STATISTICS Mean Bias Error: 0.000151609 Mean Normalized Bias Error: 2.22746 Mean Absolute Gross Error: 0.00773626 Mean Absolute Normalized Gross Error: 18.2195 Standard Deviation of Residual Distribution: 0.00979441 Fractional Gross Error: 0.176218 Fractional Bias: -0.00634921 National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Example ozone increase from O&G emissions, 6 August 2002 National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Ozone enhancements at Mesa Verde from O&G July – August 2002 August 6 National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Summary Acceptable ozone performance in WRAP annual average ozone: 42 ppb (observed) vs. 41 ppb (predicted) fractional error: 0.32, fractional bias 0.03 biases overpredict: fall through spring underpredict: summer low concentrations are overestimated National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Summary (cont’d) Nitrate performance not as good, but falls within bugle plot limits wintertime overpredictions, summertime underpredictions Largest impacts from O&G emissions on regional ozone occur in Four Corners at Mesa Verde NP on 6 August 2002 8 ppb ozone enhancement peak ozone concentrations of 65 ppb National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Summary (cont’d) Currently evaluating O&G impacts on ozone and nitrate for all Class I areas for 2002 enhanced ozone in the summer enhanced nitrate in winter Does increased ozone from O&G emissions significantly affect 1 hr and 8 hr NAAQS? ozone enhancements appear to correspond to days with high ozone National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University

Acknowledgements WRAP-RMC: emissions, meteorology Environ: assistance with CAMx National Park Service U.S. Department of the Interior Cooperative Institute for Research in the Atmosphere Colorado State University