Incremental Testing of the Community Multiscale Air Quality (CMAQ) Modeling System Version 4.7

1
Incremental Testing of the Community Multiscale
Air Quality (CMAQ) Modeling System Version 4.7

• Shawn J. Roselle, K. Wyat Appel, Kristen M.
  Foley, Prakash V. Bhave,
• Jonathan E. Pleim, Rohit Mathur, Tanya L. Otte,
  Robert C. Gilliam,
• Golam Sarwar, Christopher G. Nolte, Alice B.
  Gilliland,
• Robert W. Pinder, and Jenise L. Swall

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Acknowledgements

• Model Developers contributing to CMAQv4.7
• Jesse Bash
• Prakash Bhave
• Arastoo Pour Biazar (UAH)
• Frank Binkowski (UNC)
• Russ Bullock
• Ann Marie Carlton
• Ellen Cooter
• Bill Hutzell
• Jim Kelly (now with CARB)
• Rohit Mathur
• Sergey Napelenok
• Chris Nolte
• Tanya Otte
• Jon Pleim
• George Pouliot
• Shawn Roselle
• Golam Sarwar
• Donna Schwede

• WRF simulations
• Rob Gilliam
• Tanya Otte
• Jon Pleim
• Support model simulations, emissions
  processing, data extractions, IC/BCs
• Lucille Bender (CSC)
• Charles Chang (CSC)
• Ryan Cleary (CSC)
• Steve Howard
• Allan Huffman (CSC)
• Nancy Hwang (CSC)
• Lara Reynolds (CSC)

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Science Improvements for CMAQv4.7

• Aerosols
• Heterogeneous reaction probability (?N2O5)
• Re-derived parameterization based on Davis et al.
  (2008)
• SOA Model Enhancements (presentation by S.
  Napelenok)
• Updates isoprene SOA, sesquiterpene SOA,
  polymerization, acid-catalyzed SOA, NOx-dependent
  SOA yields, and enthalpy of vaporization (Edney
  et al., 2007)
• In-cloud SOA formation pathways (glyoxal,
  methylglyoxal) (Carlton et al., 2008)
• Changes in gas-phase chemistry mechanism,
  emissions speciation, and biogenic emissions
  model, to represent SOA precursors
• Coarse PM (poster by J. Kelly and P. Bhave)
• Semi-volatile inorganic components (NO3-, Cl-,
  and NH4) can condense and evaporate from the
  coarse mode, via dynamic mass transfer
• Nonvolatile sulfate can condense on the coarse
  mode
• Variable standard deviation of coarse mode size
  distribution
• Emissions of sea salt from the surf zone

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Science Improvements for CMAQv4.7 (cont.)

• Chemistry
• HONO enhancements (Sarwar et al., 2008)
• Heterogeneous reaction on aerosol and ground
  surfaces
• Emissions from mobile sources
• Photolysis Options (beta versions)
• In-line photolysis rate module, with aerosol
  feedback (Binkowski et al., 2008) (poster by C.
  Nolte)
• Photolysis rates adjusted using satellite-derived
  cloud information (currently table-approach only)
  (Pour Biazar et al., 2008)
• Aqueous Chemistry
• Added two organic oxidation reactions (glyoxal,
  methylglyoxal) (Carlton et al., 2008)
• Updates to Henry's Law constants based on
  literature review
• Base CB05 mechanism with Cl2 chemistry (Yarwood
  et al., 2005)
• Multi-pollutant Capability
• Include HAPs and Hg in single modeling platform
  (presentation by W. Hutzell)

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Science Improvements for CMAQv4.7 (cont.)

• In-line options
• Dry Deposition
• Moved calculation into CCTM
• Emissions (poster by J. Young)
• Integrated BEIS into CCTM
• Incorporated Plume-rise into CCTM
• Bi-directional NH3 and Hg surface flux (optional)
• For NH3, fertilizer emissions will be applied
  through the flux model (under development)
• Emissions
• Biogenic emissions added sesquiterpene
  emissions
• Speciation changes for HONO and benzene
• Sea-salt emissions
• Updated flux parameterizations surf zone
  emissions
• Used Spatial Allocator to produce ocean file

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Science Improvements for CMAQv4.7 (cont.)

• Clouds
• Convective cloud model
• Revised to reduce layer configuration differences
• Changed the integration timestep
• Resolved cloud model
• Correction in precipitation flux calculation

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Incremental Testing

• This release was incrementally tested for
  extended time periods
• January August 2006
• 12 km eastern U.S. domain (nested from 36 km
  continental U.S. domain)
• 34 vertical layers (no layer collapsing)
• Operational evaluation performed for each major
  science increment
• Transition from MM5 to WRF (poster by W. Appel)
• All simulations presented here used WRF2.2
• Benefits
• Diagnostic evaluation
• Documents the impact of each model change on
  performance
• Provides more detailed information regarding
  differences in results between model release
  versions
• Provided QA/QC for model simulations, input data,
  and implementation

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Incremental Simulations

• BASE Modified version of CMAQv4.6 that included
  chlorine chemistry
• GAMMA N2O5 New parameterization for ?N2O5
• SOA New SOA module
• HONO Surface HONO reactions and HONO emissions
• COARSE MODE Addition of Dynamic coarse mode
• CLOUDS Revised convective and resolved cloud
  models
• CMAQv4.7 Final release version

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Model Bias in SO4 --- CASTNET Weekly Observations
August 2006
January 2006
Sulfate model performance improved with cloud
model revisions
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Model Bias in NO3 --- CASTNET Weekly Observations
August 2006
January 2006
Base model used Evans and Jacob (2005)
parameterization, that included a sign error
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Model Bias in TNO3 --- CASTNET Weekly Observations
August 2006
January 2006
Again, base model used Evans and Jacob (2005)
parameterization, that included a sign error
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Model Bias in NH4 --- CASTNET Weekly Observations
August 2006
January 2006
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Model Bias in OC --- IMPROVE Daily Observations
August 2006
January 2006
Model value Observed value (µg/m3)
Model value Observed value (µg/m3)
Note primary reason for decrease in OC is change
in enthalpy of vaporization
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Model Bias in TC --- STN Daily Observations
August 2006
January 2006
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Model Bias in SO4 Wet Deposition --- NADP Weekly
Observations
August 2006
January 2006
Model value Observed value (kg/ha)
Model value Observed value (kg/ha)
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Model Bias in NO3 Wet Deposition --- NADP Weekly
Observations
August 2006
January 2006
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Model Bias in Cl Wet Deposition --- NADP Weekly
Observations
August 2006
January 2006
Model Bias improved with the addition of dynamic
coarse mode
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Model Bias in 8-hr. Max. O3 --- AQS Daily
Observations
Model value Observed value (ppb)
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Other Changes for CMAQv4.7

• MCIPv3.4 required (soon to be released)
• Diagnostic Tools (will be released later this
  year)
• Direct Decoupled Method (DDM)
• Primary carbon source apportionment model
• Sulfate tracking model
• Model options removed
• Plume-in-grid
• CB4 mechanisms
• Aero3 module and AE3 mechanisms
• RADM cloud module
• Stand-alone mercury version of CMAQ (capability
  is included in the multipollutant version)

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Model Development for Future CMAQ Releases

• Two-way Coupled WRF/CMAQ (presentations by J.
  Pleim and D. Wong)
• Chemistry
• Alternative gas-phase chemical mechanisms
  (SAPRC-2007, RACM2)
• Continued development of the inline photolysis
  module
• Aerosols
• Speciation of fine soil, non-carbon organic
  matter
• Source Apportionment of PMother
• Influence of organics on ?N2O5
• Thermodynamics of crustal/soil species
• Clouds
• Rosenbrock solver for aqueous chemistry
• Grell convective cloud module
• Dry Deposition
• Mosaic land-use approach
• National Land Cover Data (NLCD)