Jonathan Pleim1, Shawn Roselle1, Prakash Bhave1, Russell Bullock1, William Hutzell2, Deborah Luecken

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THE 2006 CMAQ RELEASE AND PLANS FOR 2007

• 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

In Partnership with the U.S. Environmental
Protection Agency
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Outline

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

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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.

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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

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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

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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

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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

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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.

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Preliminary evaluation

• Full evaluation will include
• Jan, Apr, July, Oct, 2001
• Dx 36 and 12 km
• 14 and 34 layers (see Wyat Appels poster)
• Preliminary evaluation
• Jan, July, 14 layer, Dx 12 km
• Ozone, PM

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January Average PM2.5 vs STN
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July Average PM2.5 vs STN
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July Max 8-hr Ozone CMAQv4.6 vs CMAQv4.5
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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)
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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.

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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

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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.

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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

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• 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 Commerces
  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.