THE 2006 CMAQ RELEASE AND PLANS FOR 2007

1. Jonathan Pleim1, Shawn Roselle1, Prakash Bhave1, Russell Bullock1, William Hutzell2, Deborah Luecken2, Chris Nolte1, Golam Sarwar2, Ken Schere1, Jeffrey Young1, James Godowitch1, Tanya Otte1, and Wyat Appel1 1NOAA/ARL*, RTP, NC 2USEPA/ORD, RTP, NC THE 2006 CMAQ RELEASE AND PLANS FOR 2007 * In Partnership with the U.S. Environmental Protection Agency

2. Outline • Upgrades for 2006 • CMAQ version 4.6 • MCIP version 3.2 • Preliminary evaluation • Plans for 2007 and beyond

3. Upgrades for 2006 – CMAQv4.6 • Gas Chemistry • New Carbon Bond (CB05) mechanism and associated EBI solver • 52 chemical species and 156 reactions • Summer daily maximum 1-hr ozone concentrations ~ 9% higher compared to CB-IV • Comparison of CB05 versus CB-IV will be presented by Deborah Luecken.

4. CMAQv4.6 Upgrades (cont.) • Heterogeneous Chemistry • Modified N2O5 heterogeneous hydrolysis reaction probability (g) • Now a function of sulfate, nitrate, temperature, and relative humidity • Restored gas-phase reactions involving N2O5 and H2O to CB05 and SAPRC99 mechanisms • Winter: net decrease in production of nitrate • Summer: slight increase in production of nitrate • GAMMA_N2O5 added to aerosol diagnostic file • Effects of these changes will be presented by Prakash Bhave

5. CMAQv4.6 Upgrades (cont.) • Aerosols • Updated ISORROPIA to v1.7 • Includes correction in activity coefficients for temperatures other than 298 K • Winter tests show the maximum increases of 1.8 μg/m3 and 0.5 μg/m3 for aerosol nitrate and ammonium, respectively • Set upper limit for the RH input to ISORROPIA to 95% • Reduces extreme aerosol water content in humid conditions • Ammonium and nitrate aerosol concentration also reduced

6. CMAQv4.6 Upgrades (cont.) • SAPRC99 and CB05 mechanisms expanded for Hazardous Air Pollutants (HAPs). • Larger number of gas phase HAPS than v4.5 • Several toxic metals and diesel contributions to particulate matter have been added • Details of the toxic capabilities of CMAQv4.6 will be presented by Bill Hutzell. • Updates to mercury modeling capability of CMAQv4.6 will presented by Russ Bullock

7. CMAQv4.6 Upgrades (cont.) • New PBL model (ACM2) • Combined non-local and local closure • Description of ACM2 will be presented by Jonathan Pleim • Other upgrades • Plume-in-Grid, Carbon Apportionment, and Sulfate Tracking have been updated for CB05 and AE4 • A restart file that contains the last time step of the entire 4-D concentration array has been added • Parallel I/O code library updated • New version of PARIO required for CMAQv4.6

8. MCIPv3.2 • Modified I/O API header for WRF-ARW • Center of coarse domain need not be the center of projection • Need different GRIDDESC for each WRF-ARW domain • Fix in M3Dry when not using P-X LSM in met. model • Updated headers for polar stereographic and Mercator • LWMASK added to GRIDCRO2D • Legacy options targeted for removal in the next release • RADMDry dry deposition, PBL recalculation options, radiation recalculation options, and processing data in MM5v2 format. • See the ReleaseNotes and CHANGES files for additional details.

9. Preliminary evaluation • Full evaluation will include: • Jan, Apr, July, Oct, 2001 • Dx = 36 and 12 km • 14 and 34 layers (see Wyat Appel’s poster) • Preliminary evaluation: • Jan, July, 14 layer, Dx = 12 km • Ozone, PM

10. January Average PM2.5 vs STN

11. July Average PM2.5 vs STN

12. July Max 8-hr Ozone CMAQv4.6 vs CMAQv4.5

13. Max 8-hr Ozone for July 2001 SW region (LA,TX, MS, MO, OK) Mid-Atlantic region (WV, KY, TN, VA, NC, SC, GA, AL)

14. 2007/2008 CMAQ Improvements • Aerosols • New SOA module in collaboration with HEASD • New precursors will include sesquiterpenes and isoprene. • New coarse particle chemistry module. • Transfer of volatile inorganic material between the gas phase and the coarse-particle mode will be simulated. • New algorithm to moderate biogenic emissions to account for in-canopy deposition • Substantially lower emission fluxes at night when turbulent transport is limited.

15. 2007/2008 CMAQ Improvements • In-line Photolysis (developed by F. Binkowski, CEP) • Seven wavelength bands in UV and visible • Updated absorption cross-sections and quantum yields based on Fast-J • Aerosol extinction and scattering • Grid-specific surface albedo and meteorological and chemical profiles. • Effects of clouds to be added • Cloud modeling • Adapting WRF/CHEM convective cloud model for CMAQ in collaboration with Georg Grell (NOAA/OAR) • Cloud mixing includes updraft, downdraft, and compensating subsidence. • Updating the aqueous chemistry module in CMAQ. • More detailed aqueous mechanism

16. Satellite data assimilation • Collaborative project with University of Alabama at Huntsville and NASA/MSFC to use satellite information to improve meteorology and chemistry modeling • Solar insolation derived from GOES assimilated into met. model (MM5 and WRF) • Photolysis rates derived from GOES and model information used in CMAQ • In future, satellite-derived skin temperature can be used to nudge soil moisture.

17. 2-Way WRF-CMAQ coupling • Synchronous meteorology and chemistry calculations • Allow chemical feedback to meteorology • Aerosol feedback to the radiation model. • Integrated resolved-scale microphysics and aqueous chemistry • Indirect effects of aerosols on microphysics • Consistent air quality modeling in either 2-way coupled or 1-way sequential execution. • Prototype anticipated in 2008

18. Disclaimer: The research presented here was performed under the Memorandum of Understanding between the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Commerce’s National Oceanic and Atmospheric Administration (NOAA) and under agreement number DW13921548. This work constitutes a contribution to the NOAA Air Quality Program. Although it has been reviewed by EPA and NOAA and approved for publication, it does not necessarily reflect their views or policies.