Application of Models-3/CMAQ to Phoenix Airshed

1. Application of Models-3/CMAQ to Phoenix Airshed Sang-Mi Lee and Harindra J. S. Fernando Environmental Fluid Dynamics Program Arizona State University

2. Outline • Study Area – Phoenix Basin • MM5 Simulation • Models-3/CMAQ Result • Process Analysis of CMAQ

3. Topography of Phoenix and its Surroundings

4. Air Quality in Phoenix • Non-Attainment Area of the NAAQS for O3, PM10 , and CO • PAFEX (Phoenix Air Flow Experiment) • PAFEX-1 (January 14 - February 1, 1998) • PAFEX-2 (July 1 - September 15, 1998) • Spatial and Vertical distribution of Pollutants • Mean & turbulent measurements of meteorology • 1998 Phoenix Ozone Study (June 11 - 30, 2001) • Aircraft measurements for VOC & Oxides • 2001 Phoenix Ozone Study (June 11 - 30, 2001) • 3-D Spatial & Temporal distribution of Ozone & Oxides • As well as meteorology

5. Design of Numerical Experiments • Study Case  0400 LST July 22 – 0000 LST July 24, 1996 • Spatial Dimension • 2 km horizontal grid spacing • 31 vertical layers • Meteorological data MM5 + FDDA  IV & BV : NCEP Eta Analysis 40 km output • Emission data • Prepared with EPS2 for UAM • From Arizona Department of Environmental Quality • Initial value & Boundary value Near surface concentration : routine monitoring data Upper level :Ozone & VOC aircraft measurement in 1998

6. Ground Level Wind Field 0400 LST July 22nd – 2300 LST July 23rd

7. Validation of MM5 output

8. Validation of MM5 output Bowen Ratio ~ 4

9. Correlation between MM5 vs Observations Temperature u-component v-component (r=0.9) (r=0.4) (r=0.4)

10. Ground Level Ozone Concentration 0400 LST July 22nd – 2300 LST July 23rd Superstition Mts Downtown Phoenix Mesa Tempe

11. Ground Level Ozone Concentration Mountain Area Downtown Phoenix

12. Emission Inventory Superstition Mts Superstition Mts Downtown Phoenix Downtown Phoenix Mesa Mesa Tempe Tempe

13. Emission vs. concentration Downtown Eastern Valley

14. Temporal & Vertical Variation of Ozone • 9 11 13 15 17 19 21 23 00 02 04 • Local Time

15. Prediction vs. Observation: O3

16. Prediction vs. Observation: CO

17. Observation: PBL growth & Ozone PBL Growth Ozone June 25th, 2001

18. 1-D Column Application & Budget of each Process

19. Downstream Site (Blue Point Bridge) Downtown Site (Super Site) Superstition Mts Downtown Phoenix Mesa Tempe

20. Downtown vs Downstream

21. Downtown vs Downstream

22. Schematics for Daytime Ozone Physics Chemistry 0/+ Vertical Mixing + Deposition - Horizontal Transport + Chemistry + Vertical Mixing - High Ozone Reservoir Maximum Ground Ozone Chemistry -- Vertical Mixing ++ Deposition - Middle Level Ozone

23. Schematics for Nighttime Ozone Physics Chemistry -/0 Vertical Intermittent Mixing - Ozone Reservoir Ozone Reservoir Chemistry - - Intermittent Turbulence ++ Horizontal Transport + (Gust front, K-H instability +) Ozone Free Air Mass

24. Summary • Meteorology in Phoenix area was reasonably reproduced by MM5. The correlation coefficients between MM5 and observations at surface layer were as high as 0.9 for temperature and 0.4 for both u- and v- wind components. • Downstream region has higher ozone concentration than downtown region due to advection by local circulation as well as active NOx chemistry • In Phoenix metropolitan area, the increase of ground level ozone concentration was contributed by vertical dispersion rather than photochemical construction • In downstream of the urban area, ground level ozone was increased by chemical production as well as vertical dispersion