Community Multiscale Air Quality Modeling System CMAQ

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Community Multiscale Air Quality Modeling
SystemCMAQ

• Air Quality Data Summit
• February 2008

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CMAQ System Overview Data Flow
Emissions Data Emis Models - Data (Mobile /
other models)
Meteorological Data Met Models - Data (MM-5 /
WRF)
Emissions Processing - Data (SMOKE)
Met-Chemistry Interface Processor - Data (MCIP)
Chemical Transport Model
CONC
Governing Equations
Gas Phase Chemistry
Cloud Chemistry
Extraction End User Files
Aerosols Chemistry
Transport
DEP
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CMAQ Data Types and Attributes

• CMAQ Input Data
• Meteorology gridded (x,y,z), hourly data for
  more than 50 parameters
• Emissions gridded (x,y,z), hourly data for 30
  gas and particle species
• CMAQ Output Data
• Concentration gridded hourly average
• CONC file All species all layers
• Extraction files ground level O3, NO, NO2,
  NH3, OH, other gases, and fine and course
  particle species
• Deposition gridded, hourly total wet and dry
• Oxidized and reduced nitrogen species, sulfur,
  ozone, and other species

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CMAQ Data for 2002

• Supplier
• EPA OAQPS and ORD
• Data developed as part of 2002 Multi-Pollutant
  Air Quality Modeling Platform
• Usage
• CMAQ Evaluation Improvement
• EPA Policy Analyses and Regulatory Applications
• Connections to Other Systems
• Data currently stored inside EPA firewall at
  NCC
• Data are loosely coupled to
• Visualization (PAVE/VERDI)
• Model evaluation (AMET)
• Decision support (BENMap)
• Other analyses (e.g., Data Fusion,
  Accountability)

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Spatial Coverage of 2002 CMAQ Data Continental US
Domain 36 x 36 km x 14 layers Eastern Western
Domains 12 x 12 km x 14 layers
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CMAQ Data Enhancements

• Implementing improved internal data base
  management procedures
• Possible development of a CMAQ Applications
  Management Framework with attributes and
  functionality similar to the Emissions Modeling
  Framework
• Exploring public access to 2002 data via
  Community Modeling Analysis System (CMAS)

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Issues w/re Access to CMAQ Data (1)

• What are the specific user needs
  (internal/external)?
• How will these be defined?
• What is the most IT-efficient way to provide
  access to users inside/outside EPA?
• Data volume issues
• Outputs from 12 km Eastern Domain annual run
  3,000GB
• Firewall issues (external users)
• Should EPA provide data for all species in all
  layers?
• If so, what procedures will be available to users
  to subset data in space and time (leverage
  existing procedures, e.g., RSIG)?
• How will user questions/access problems be
  addressed?
• Questions Technical issues beyond what metadata
  can address
• Access IT issues

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Issues w/re Access to CMAQ Data (2)

• CMAQ applications are often evolutionary
• Specific scenarios may be updated as new inputs
  and science become available
• Potential for consistency/comparability issues
  across different CMAQ applications
• So....
• Increased emphasis on metadata, version tracking,
  and other documentation
• How will the user community be notified of
  updates to CMAQ data?
• CMAQ outputs from regulatory / research
  applications must be kept internal until rules /
  journal articles are published..this results in
  potentially large time-lag between completion of
  model application and public release of data