1 Asheville Air Quality Megan Stone

2 Clean Smokestacks Act Passed in 2002 by the General Assembly of North Carolina Passed in 2002 by the General Assembly of North Carolina “An act to improve air quality in the state by imposing limits on the emission of certain pollutants from certain facilities that burn coal to generate electricity…” “An act to improve air quality in the state by imposing limits on the emission of certain pollutants from certain facilities that burn coal to generate electricity…”

3 Clean Smokestacks Act Requires Progress Energy and Duke Energy to submit annual reports containing air quality information. Requires Progress Energy and Duke Energy to submit annual reports containing air quality information. Progress Energy has spent $190 million dollars at the Asheville plant for technologies to reduce emissions. Progress Energy has spent $190 million dollars at the Asheville plant for technologies to reduce emissions.

4 Clean Smokestacks Act Western North Carolina has a huge ozone problem. Western North Carolina has a huge ozone problem. Cutting NOx emissions would reduce the amount of ozone in the area. Cutting NOx emissions would reduce the amount of ozone in the area. Scrubbers have been installed in the Asheville Power Plant Scrubbers have been installed in the Asheville Power Plant

5 Formation of Ozone

6 Scrubbers NOx + NH 4  H 2 O(g) + N 2

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10 Correlation Coefficient Measures the linear relationship between two variables. Measures the linear relationship between two variables. The correlation coefficient (r 2 ) is always between -1 and +1. The closer the correlation is to +/-1, the closer to a perfect linear relationship. The correlation coefficient (r 2 ) is always between -1 and +1. The closer the correlation is to +/-1, the closer to a perfect linear relationship.

11 Correlation Coefficient Ozone vs. Sunlight Ozone vs. Sunlight Ozone vs. VOCs Ozone vs. VOCs Ozone vs. NOx Ozone vs. NOx

12 Sunlight vs. Ozone Hypothesis: More sunlight yields more ozone. Hypothesis: More sunlight yields more ozone. Therefore, R 2 > 0 for a correlation between ozone and sunlight amount. Retrieved daily “clear” observations for 2006/2007 summers from NCDC  calculated daily percentages (10am, 1pm, and 4pm) Retrieved daily “clear” observations for 2006/2007 summers from NCDC  calculated daily percentages (10am, 1pm, and 4pm)

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April May June July August September October Monthly Sunlight %Ozone (ppm)

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April May June July August Sept Oct Monthly Sunlight % Ozone (ppm)

17 Sunlight vs. Ozone 2006: R 2 =  Practically no correlation 2006: R 2 =  Practically no correlation 2007: R 2 =  Much stronger positive correlation 2007: R 2 =  Much stronger positive correlation Conclusion: Both are positive correlations. Conclusion: Both are positive correlations. (But what happened in 2006?)

18 Ozone vs. VOCs The state of NC releases estimates of how much VOCs are released by humans per month every three years. The state of NC releases estimates of how much VOCs are released by humans per month every three years. VOCs are not monitored. VOCs are not monitored. Hypothesis: An increase of VOCs yields an increase of ozone. Therefore, R 2 > 0 for a correlation between ozone and VOCs. Hypothesis: An increase of VOCs yields an increase of ozone. Therefore, R 2 > 0 for a correlation between ozone and VOCs.

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MonthOzoneVOC April May June July August Sept Oct R 2 R 2 =

21 NOx vs. Ozone Like VOCs, NOx emissions are not monitored like ozone. Like VOCs, NOx emissions are not monitored like ozone. Division of Air Quality releases estimates of how much the Asheville Plant emits monthly every three years. Division of Air Quality releases estimates of how much the Asheville Plant emits monthly every three years. Last time was 2005 (before any scrubbers were installed) Last time was 2005 (before any scrubbers were installed)

22 NOx vs. Ozone Hypothesis: An increase of NOX yields an increase of ozone. Hypothesis: An increase of NOX yields an increase of ozone. Therefore, R 2 > 0 for a correlation between ozone and NOx. Therefore, R 2 > 0 for a correlation between ozone and NOx.

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NOx vs. Ozone MonthOzoneNox April May June July August Sept Oct R 2 R 2 = Negative correlation??????????

25 Explanation Sunlight reacts with NOx Sunlight reacts with NOx NOx + sunlight  NO + O O + O 2  O 3

26 Explanation The ozone created from this reaction then reacts with more NOx… NOx + O 3  NOx + O 2 No net gain or loss of ozone!

27 Explanation It’s the addition of VOCs into the atmosphere that alters the chemistry which contributes to elevated levels of ozone. It’s the addition of VOCs into the atmosphere that alters the chemistry which contributes to elevated levels of ozone. NOx + VOC + sunlight  O 3

28 Ozone Prediction Predicting ozone levels is a lot more complicated than what we think. Predicting ozone levels is a lot more complicated than what we think.

29 New Hypothesis In order to reduce ozone levels, we must reduce the sunlight or VOC amounts… In order to reduce ozone levels, we must reduce the sunlight or VOC amounts… We cannot stop sunlight, so in order to decrease ozone, we must accompany the NOx reduction with a VOC reduction. We cannot stop sunlight, so in order to decrease ozone, we must accompany the NOx reduction with a VOC reduction. Is it possible? Is it possible?

30 The Future Analysis of 2008 data – is there still a negative correlation between NOx and Ozone? Analysis of 2008 data – is there still a negative correlation between NOx and Ozone? Why was there a natural decreasing trend in ozone? Why was there a natural decreasing trend in ozone? Possibility of a lag? Possibility of a lag?

31 References Tropospheric Air Pollution: Ozone, Airborne Toxics, Polycuclic Aromatic Hydrocarbons, and Particles. Pitts & Pitts Tropospheric Air Pollution: Ozone, Airborne Toxics, Polycuclic Aromatic Hydrocarbons, and Particles. Pitts & Pitts Statistical Methods in the Atmospheric Sciences. Daniel S. Wilkes Statistical Methods in the Atmospheric Sciences. Daniel S. Wilkes North American Mesoscale Model – Community Multiscale Air Quality Model Ozone Forecast Verification Study For Knoxville, TN (Summer 2005). Loren C. Marz North American Mesoscale Model – Community Multiscale Air Quality Model Ozone Forecast Verification Study For Knoxville, TN (Summer 2005). Loren C. Marz