1. Photochemical Model Performance and Consistency
James W. Boylan
Georgia Department of Natural Resources - VISTAS
Kirk Baker
Lake Michigan Air Directors Consortium - MRPO
National RPO Modeling Meeting
Denver, CO
May 26, 2004

2. Outline
Comparison of Model Results to IMPROVE Measurements (24-hour average)
MRPO, VISTAS, and MANE-VU
July 13–27, 1999 and January 1-19, 2002
SHEN, MACA, and UPBU
Comparison of Model Results to Pittsburgh Super Site Measurements (Hourly)
MRPO and VISTAS
July 13–27, 1999

3. Summary of Modeling Systems
MRPO
VISTAS
MANE-VU
AQ Model
CAMx (CB-IV)
CMAQ (CB-IV)
CMAQ (SAPRC-99)
Meteorological Model (MM5)
Pleim-Xiu LSM Pleim-Chang PBL
Pleim-Xiu LSM Pleim-Chang PBL
Emissions Model
EMS-2003
SMOKE
Emissions Inventory
1999 NEI v2 CMU NH3
1999 NEI v.2 CMU/EPA NH3
1999 NEI v.2 EGAS
Horizontal Grid Structure
Eastern US (36 km)
Continental US (36 km)
Continental US (36 km)
Vertical Layers
14 (6km)
19 (15km)
9 (15 km)
Boundary Conditions
EPA Default
GEOS-CHEM Seasonal (2001)

4. Comparison of Model Results to IMPROVE Measurements

5. IMPROVE vs. Models

6. IMPROVE vs. Models

7. IMPROVE vs. Models

8. IMPROVE vs. Models

9. IMPROVE vs. Models

10. IMPROVE vs. Models

19. Comparison of Model Results to Pittsburgh Super Site Measurements

20. Pittsburgh Super Site – July 2001

26. Summary
Given the preliminary nature and diverse modeling approaches the results seem to agree fairly well
None of the modeling approaches seems to be consistently closer to the observed values; performance varies by day and specie
The three modeling systems compare reasonably well to the IMPROVE measurements on ~ 70% of the days, but can show large discrepancies on the other days.
Hourly model output at the Pittsburgh Super Site are very consistent on a diurnal and synoptic scale
Only one station but the results are encouraging
Need to evaluate the response of the various modeling systems to changes in emissions at specific receptor locations.