1. Sensitivity of PM 2.5 Species to Emissions in the Southeast Sun-Kyoung Park and Armistead G. Russell Georgia Institute of Technology Sensitivity of PM 2.5 species to Emissions in the Southeast

2. OVERVIEW Contents Model Domain Meteorological Input Input of SMOKE and Modules in CMAQ CMAQ 4.2.2 vs. 4.3 Sensitivity of PM 2.5 to Emissions Conclusion Comparison between CMAQ 4.2.2 and 4.3 Sensitivity of PM 2.5 to emissions in the Southeast for July 2001 and January 2002 using Models-3 (CMAQ 4.3/MM5/SMOKE) Sensitivity of PM 2.5 species to Emissions in the Southeast

3. 1. Model Domain CMAQ horizontal domain and the vertical structure. Sensitivity of PM 2.5 species to Emissions in the Southeast ModelCMAQMM5 Grid size36 km12 km36 km12 km Dimension147 x 11121 x 18164 x 12827 x 24 Coordinate of the origin(-2,628, -1,980 km)(1,044, -720 km)(-2,952, -2,304 km)(1,008, -756 km) Number of vertical layer925 Top pressure of the model domain 100 hPa

4. 2. Meteorological Input MM5 version 3.5.3: Simple ice microphysics Kain-Fritsch cumulus scheme Rapid radiative transfer model Pleim Chang planetary boundary layer Pleim-Xiu land surface model Four Dimensional Data Assimilation: NCEP Eta model outputs for the GCIP project NCEP ADP Observational data Evaluation: TDL surface hourly data Sensitivity of PM 2.5 species to Emissions in the Southeast

5. 2. Meteorological Input Sensitivity of PM 2.5 species to Emissions in the Southeast Temperature (K)Specific Humidity (g/kg)Wind Speed (m/sec) July 2001 January 2002 RMSE

6. Statistical benchmark (Emery et al., (2001)) Emery, C., E. Tai and G. Yarwood, 2001. “Enhanced meteorological modeling and performance evaluation for two Texas episodes”, report to the Texas National Reesources Conservation Commision, prepared by ENVIRON, International Corp, Novato, CA 2. Meteorological Input Sensitivity of PM 2.5 species to Emissions in the Southeast

7. 3. Input of SMOKE and Modules in CMAQ Input of SMOKE Emissions inventory developed by GA Tech for the state of Georgia and 1999 National emissions inventory for other states EGAS 4.0 growth factors and existing control strategy to project the 1999 emissions to 2001 and 2002 emissions Modules in CMAQ Chemical mechanism: SAPRC-99 Chemistry solver: modified Euler backward iterative (MEBI) method Cloud: the regional acid deposition model (RADM) Aerosol dynamics: AERO3 Deposition velocities of aerosols: AERO_DEPV2 Horizontal and vertical advection: piecewise parabolic method (PPM) Minimum vertical eddy coefficient: 0.3 m 2 /sec. Sensitivity of PM 2.5 species to Emissions in the Southeast

8. 4. CMAQ 4.2.2 vs. 4.3 (daily PM 2.5) The performance of CMAQ was evaluated with measured data of SEARCH and ASACA stations JST

9. 4. CMAQ 4.2.2 vs. 4.3 (daily PM 2.5, July 2001) 36 km (version 4.2.2) 36 km (version 4.3) 12 km (version 4.2.2) 12 km (version 4.3) SulfateAmmoniumNitrate PM 2.5Organic CarbonElemental Carbon OBS x 2 OBS x 0.5 Sensitivity of PM 2.5 species to Emissions in the Southeast

10. 4. CMAQ 4.2.2 vs. 4.3 (daily PM 2.5, January 2002) SulfateNitrateAmmonium Elemental CarbonOrganic CarbonPM 2.5 OBS x 2 OBS x 0.5 Sensitivity of PM 2.5 species to Emissions in the Southeast 36 km (version 4.2.2) 36 km (version 4.3) 12 km (version 4.2.2) 12 km (version 4.3)

11. 4. CMAQ 4.2.2 vs. 4.3 (hourly gas phase species, July 2001) CO HNO3NOyPM 2.5 O3O3 MBE (ppb) MNB (%) MGE (ppb) MNGE (%) Version 4.2.2 5.3813.724.8344.35 Version 4.3 11.1621.620.2438.1 Statistics of O 3 (12 km domain) O3O3 OBS x 2 OBS x 0.5 Sensitivity of PM 2.5 species to Emissions in the Southeast 36 km (version 4.2.2) 36 km (version 4.3) 12 km (version 4.2.2) 12 km (version 4.3)

12. Performance of CMAQ for PM 2.5 species Sulfate: overestimated in July 2001 good in January 2002 Nitrate: overestimated Ammonium: good Elemental Carbon: overestimated Organic carbon: from version 4.2.2 to 4.3, the performance is improved markedly after the secondary organic aerosol algorithm has been modified to make the gas-particle partitioning of semi- volatiles reversible PM 2.5: overestimated mainly due to the overestimation of the crustal elements (primary PM 2.5) Sensitivity of PM 2.5 species to Emissions in the Southeast 4. CMAQ 4.2.2 vs. 4.3 (hourly gas phase species, July 2001)

13. 5. Sensitivity of PM 2.5 to Emissions Sulfate: Major species of the PM 2.5 in the Southeast. Sources: anthropogenic emissions Sensitivity of emissions to sulfate  sensitivity of emissions to PM 2.5 20% reduction of SO 2 20% reduction of NH 3 20% reduction of NH 3 and SO 2 Sensitivity of PM 2.5 species to Emissions in the Southeast

14. Sulfate Nitrate July 2001 January 2002 5. Sensitivity of PM 2.5 to Emissions (20% reduction of SO 2 ) Sensitivity of PM 2.5 species to Emissions in the Southeast : sensitivity, : concentration

15. Ammonium PM 2.5 July 2001 January 2002 5. Sensitivity of PM 2.5 to Emissions (20% reduction of SO 2 ) Sensitivity of PM 2.5 species to Emissions in the Southeast : sensitivity, : concentration  mass

16. SulfateNitrate 5. Sensitivity of PM 2.5 to Emissions (20% reduction of NH 3 ) July 2001 January 2002 : sensitivity, : concentration Sensitivity of PM 2.5 species to Emissions in the Southeast

17. 5. Sensitivity of PM 2.5 to Emissions (20% reduction of NH 3 ) PM 2.5Ammonium July 2001 Sensitivity of PM 2.5 species to Emissions in the Southeast : sensitivity, : concentration  mass January 2002

18. SulfateNitrate July 2001 January 2002 5. Sensitivity of PM 2.5 to Emissions (20% reduction of NH 3 and SO 2 ) Sensitivity of PM 2.5 species to Emissions in the Southeast : sensitivity, : concentration

19. AmmoniumPM 2.5 July 2001 5. Sensitivity of PM 2.5 to Emissions (20% reduction of NH 3 and SO 2 ) Sensitivity of PM 2.5 species to Emissions in the Southeast : sensitivity, : concentration  mass January 2002

20. 5. Sensitivity of PM 2.5 to Emissions Sensitivity of PM 2.5 species to Emissions in the Southeast

21. The sensitivity of PM 2.5 to a 20% reduction of NH 3 : high in January 2002 SO 2 : high in July 2001 NH 3 and SO 2 : high in both January 2002 and July 2001 20 % of SO 2 20 % of NH 3 20 % of NH 3 and SO 2 July 2001 -6.0 % ( -1.61  g/m 3 ) -2.19 % (-0.59  g/m 3 ) -8.01 % (-2.15  g/m 3 ) January 2002 -0.96 % (-0.26  g/m 3 ) -5.62 % (-1.53  g/m 3 ) -6.4 % (-1.74  g/m 3 ) Sensitivity of PM 2.5 species to Emissions in the Southeast 5. Sensitivity of PM 2.5 to Emissions

22. 6. Summary CMAQ 4.3 improved markedly in simulation of organic carbon concentration. However, model still overestimates primary PM 2.5 species. When SO 2 is reduced, sulfate concentrations decreased, but nitrate concentrations increased. Thus, only SO 2 reduction was not efficient way to reduce the PM 2.5 in winter time, when the nitrate concentrations are relatively high. When NH 3 is reduced, nitrate and ammonium decreased, but sulfate concentrations did not change much. Thus, NH 3 reduction did not decrease PM 2.5 in summer time, when the sulfate concentrations are relatively high. When NH 3 and SO 2 are both reduced, nitrate, sulfate and ammonium concentrations decreased significantly both summer and winter. Future research will include the sensitivity of emissions for different geographic locations. Sensitivity of PM 2.5 species to Emissions in the Southeast