1. Georgia Institute of Technology SAMI Aerosol Modeling: Performance Evaluation & Future Year Simulations Talat Odman Georgia Institute of Technology SAMI Visibility Workshop August 24, 2000

2. Georgia Institute of Technology Outline Overview of the modeling system –One atmosphere approach Performance evaluation –Ozone and wet deposition –Aerosols Future year results –2010 on-the-way strategy –Aerosols

3. Georgia Institute of Technology The Models Meteorology: Regional Atmospheric Modeling System (RAMS) –temperature, air density, wind speed and direction, total solar radiation, ultraviolet radiation, mixing height, turbulent momentum diffusivity, precipitation, cloud parameters Emissions : Emission Modeling System (EMS-95) –Gas : NO x, ROG, CO, NH 3, SO 2 –Aerosols : OC, EC, Ca, Mg, K, NO 3, SO 4, other PM Air Quality : Urban-to-Regional Multiscale Model (URM)

4. Georgia Institute of Technology URM Model Integrated “one atmosphere” modeling approach Three-dimensional Eulerian photochemical model –Finite element, multiscale transport scheme (Odman & Russell, 1991) –Gas-phase chemistry SAPRC-93 mechanism (Carter, 1994) –Aerosol dynamics Sectional approach (Gelbard and Seinfeld, 1980) ISORROPIA thermodynamic equilibrium (Nenes, et al., 1998) Organic aerosol yields (Pandis, et al., 1992) –Acid Deposition Wet: Reactive Scavenging Module (Berkowitz, et al., 1989) Dry: three-resistance approach (Wesely, 1989) –Sensitivity analysis Direct decoupled method (Yang, et al., 1997)

5. Georgia Institute of Technology Aerosol Module Inorganic aerosols - ISORROPIA –sulfate, nitrate, ammonium, chloride, sodium, hydrogen ion –condensation/evaporation (thermodynamic equilibrium) Organic aerosols –lumped sum of numerous condensable organic species –experimental aerosol yields from VOC oxidation Inert Species –EC, Mg, Ca, K, other PM Sectional Size Distribution

6. Georgia Institute of Technology Reactive Scavenging Module Scavenging processes for gas and aerosol species Vertical convective transport in clouds Inputs –Meteorological Parameters –Concentration Profiles: SO 2, SO 4, O 3, NHO 3, NO 3, H 2 O 2, NH 3, NH 4 Outputs –Updated Concentration Profiles –Deposition Fluxes SO 2, SO 4, NO 3, H 2 O 2, NH 4, Mg, Ca, H-ion

7. Georgia Institute of Technology Modeling Domain and Grid

8. Georgia Institute of Technology Basecase Episodes July 11 -19, 1995 (GIT) May 24 -29, 1995 (GIT) May 11 -17, 1993 (GIT) March 23 -31, 1993 (GIT) February 8 - 13, 1994 (GIT) July 23 - 31, 1991 (GIT) June 24 - 29, 1992 (TVA) August 3 - 11, 1991 (TVA) April 26 - May 3, 1995 (TVA)

9. Georgia Institute of Technology Ozone Performance

10. Georgia Institute of Technology Ozone Performance

11. Georgia Institute of Technology Wet Deposition Bias and Error

12. Georgia Institute of Technology Wet Deposition Bias and Error

13. Georgia Institute of Technology Wet Deposition Bias and Error

14. Georgia Institute of Technology IMPROVE Monitoring Stations 8. Cape Romain (SC) 9. Shenandoah (VA) 10. Shining Rock (NC) 11. Sipsy (AL) 12. Upper Buffalo (AR) 13. Washington, D.C. 1. Brigantine (NJ) 2. Dolly Sods/Otter Creek (WV) 3. Great Smoky Mountains (TN) 4. Jefferson/James River Face (VA) 5. Lye Brook (VT) 6. Mammoth Cave (KY) 7. Okefenokee (GA)

15. Georgia Institute of Technology IMPROVE Monitoring Locations

16. Georgia Institute of Technology Fine Sulfate Bias and Error

17. Georgia Institute of Technology Fine Nitrate Bias and Error

18. Georgia Institute of Technology Fine Ammonium Bias and Error

19. Georgia Institute of Technology Fine Organics Bias and Error

20. Georgia Institute of Technology Fine Elem. Carbon Bias and Error

21. Georgia Institute of Technology Fine Soils Bias and Error

22. Georgia Institute of Technology Fine PM Bias and Error

23. Georgia Institute of Technology PM 10 Bias and Error

24. Georgia Institute of Technology Coarse PM Bias and Error

25. Georgia Institute of Technology Speciation of PM 2.5 Components Components of PM 2.5 –sulfate, nitrate, ammonium, organics, EC, soils, and “others” Ammonium –IMPROVE: assume (NH 4 )HSO 4 and NH 4 NO 3 Organics –IMPROVE: organic carbon mass x 1.4 Soils –IMPROVE: Ca, Si, Fe, Ti, Al –Model: Ca and unspeciated PM “Others” –IMPROVE: P, Cl, K, V, Cr, Mn, Ni, Cu, Zn, As, Pb, Se, Br, Rb, Sr, Zr, Mo, and Unidentified Component (OC, H 2 O, etc) –Model: Na, Cl, H, K, Mg

26. Georgia Institute of Technology July 15, 1995 Class 5 Visibility Day

27. Georgia Institute of Technology May 27, 1995 Class 4 Visibility Day

28. Georgia Institute of Technology May 15, 1993 Class 3 Visibility Day

29. Georgia Institute of Technology March 27, 1993 Class 1 Visibility Day

30. Georgia Institute of Technology 2010 OTW Episodes July95 on-the-way Episode –NOx emissions decreased by 39% –SO2 emissions decreased by 32% May95 on-the-way Episode –NOx emissions decreased by 33% –SO2 emissions decreased by 17% May93 on-the-way Episode –NOx emissions decreased by 32% –SO2 emissions decreased by 30%

31. Georgia Institute of Technology Change in SO 2 Emissions on July 15, 1995 and May 27, 1995

32. Georgia Institute of Technology Change in NOx Emissions on July 15, 1995 and May 27, 1995

33. Georgia Institute of Technology Sulfate on July 15, 1995 (Class 5)

34. Georgia Institute of Technology Sulfate on May 27, 1995 (Class 4)

35. Georgia Institute of Technology Sulfate on May 15, 1993 (Class 3)

36. Georgia Institute of Technology Nitrate on July 15, 1995 (Class 5)

37. Georgia Institute of Technology Nitrate on May 27, 1995 (Class 4)

38. Georgia Institute of Technology Nitrate on May 15, 1993 (Class 3)

39. Georgia Institute of Technology Ammonium on July 15, 1995 (Class 5)

40. Georgia Institute of Technology Ammonium on May 27, 1995 (Class 4)

41. Georgia Institute of Technology Ammonium on May 15, 1993 (Class 3)

42. Georgia Institute of Technology Organics on July 15, 1995 (Class 5)

43. Georgia Institute of Technology Organics on May 27, 1995 (Class 4)

44. Georgia Institute of Technology Organics on May 15, 1993 (Class 3)

45. Georgia Institute of Technology PM 2.5 on July 15, 1995 (Class 5)

46. Georgia Institute of Technology PM 2.5 on May 27, 1995 (Class 4)

47. Georgia Institute of Technology PM 2.5 on May 15, 1993 (Class 3)

48. Georgia Institute of Technology

53. Conclusions Integrated modeling system has been developed. Performance for ozone, aerosols, and deposition (wet and dry) is generally satisfactory. –Aerosol nitrate and soils are overestimated –Performance for February 1994 episode is relatively poor Future year sulfate, nitrate, ammonium, and PM 2.5 increases/decreases depending on the site and episode day. –Sulfate increases might be explained by SO 2 heterogeneous reaction pathways (H 2 O 2 and O 3 )

54. Georgia Institute of Technology SO 2 on May 27, 1995

55. Georgia Institute of Technology H 2 O 2 on May 27, 1995

56. Georgia Institute of Technology Aerosol Module Inorganic aerosols - ISORROPIA –sulfate, nitrate, ammonium, chloride, sodium, hydrogen ion –temperature, pressure, relative humidity –condensation/evaporation (thermodynamic equilibrium) Organic aerosols –lumped sum of numerous condensable organic species –experimental aerosol yields from VOC oxidation Inert Species –EC, Mg, Ca, K, other PM Size Distribution –moving sectional approach

57. Georgia Institute of Technology Aerosol Size Distribution “Engineering Model” with four size bins: 0.039  m - 0.156  m 0.156  m - 0.625  m 0.625  m - 2.50  m 2.50  m - 10.0  m

58. Georgia Institute of Technology July 12, 1995

59. Georgia Institute of Technology July 19, 1995

60. Georgia Institute of Technology May 24, 1995

61. Georgia Institute of Technology May 12, 1993

62. Georgia Institute of Technology March 24, 1993

63. Georgia Institute of Technology March 31, 1993

64. Georgia Institute of Technology February 9, 1994

65. Georgia Institute of Technology February 12, 1994

66. Georgia Institute of Technology Sulfate Wet Deposition for July 1995

67. Georgia Institute of Technology Sulfate Wet Deposition for May 1995

68. Georgia Institute of Technology Sulfate Wet Deposition for May 1993

69. Georgia Institute of Technology Nitrate Wet Deposition for July 1995

70. Georgia Institute of Technology Nitrate Wet Deposition for May 1995

71. Georgia Institute of Technology Nitrate Wet Deposition for May 1993

72. Georgia Institute of Technology Ammonium Wet Deposition for July 1995

73. Georgia Institute of Technology Ammonium Wet Deposition for May 1995

74. Georgia Institute of Technology Ammonium Wet Deposition for May 1993

75. Georgia Institute of Technology Hydrogen Ion Wet Deposition for July 1995

76. Georgia Institute of Technology Hydrogen Ion Wet Deposition for May 1995

77. Georgia Institute of Technology Hydrogen Ion Wet Deposition for May 1993

78. Georgia Institute of Technology