Description:

The U.S. EPA developed the Community Multiscale Air Quality (CMAQ) system to apply a “one atmosphere” multiscale and multi-pollutant modeling approach based mainly on the “first principles” description of the atmosphere. The multiscale capability is supported by the governing diffusion equation in a generalized coordinate system that handles many map projections and vertical coordinate systems, a scheme that maintains dynamic consistency with the upstream (i.e., off-line) meteorology model, and a nesting approach. The multi-pollutant (i.e., tropospheric ozone, acid deposition, particulates, air toxics, mercury, nitrogen loading, and visibility) capability is provided by the generalized chemistry mechanism description, general numerical solver, and comprehensive description of gaseous and aqueous chemistry and modal aerosol dynamics. Input emission data sets for CMAQ are estimated using the SMOKE emissions modeling and processing system. Typical retrospective model applications have employed as input three-dimensional descriptions of prevalent meteorological conditions simulated by the MM5 and Weather Research and Forecasting (WRF) meteorological models, while air quality forecast applications have linked the CMAQ model with the National Weather Service’s operational North American Mesoscale (NAM) model.

Record Details:

Record Type:MODEL

Product Published Date:01/20/2004

Record Last Revised:11/16/2009

Record ID: 75894

Show Additional Record Data

Model Detail:

Model Evaluation :CMAQ model evaluations have been conducted for a variety of time periods and pollutant species. The model is continuously being evaluated using data from operational routine monitoring networks for ozone and fine particulate matter in the U.S. Diagnostic evaluations are conducted using surface and aloft observed data from intensive field studies, such as the 2006 Texas Air Quality Study, 2004 ICARTT study, the Southern Oxidants Study and the Supersites intensives. Additional details on model evaluation activities can be found at: http://www.epa.gov/asmdnerl/ModelEvaluation/index.html

The CMAQ user community also performs detailed evaluation and verification against observations as well as sensitivity and uncertainty analysis. The results from these are presented at the annual CMAS meeting; presentation and extended abstracts can be found at: http://www.cmascenter.org/conference.cfm

Also see: Special issue on Model Evaluation: Evaluation of Urban and Regional Eulerian Air Quality Models, Atmospheric Environment, Volume 40, Issue 26, August 2006.

Model URL :http://www.epa.gov/asmdnerl/CMAQ/cmaq_model.html

Model Guidance Documents :User's documentation, scripts, and example tutorials may be found on the CMAQ model download site. and the CMAQ model home page.

User information can also be obtained from the Models-3 CMAQ listserver. Please subscribe at:
http://lists.unc.edu/read/all_forums/subscribe?name=m3list

Model Decision Documents :Model Overview: Byun and Schere, 2006, Applied Mechanics Reviews, 59:51-77.

CMAQ Science Documentation:

• Comprehensive science documents

  Additional information: www.cmaq-model.org
  
  Model Download Information :The latest version of CMAQ and SMOKE is available for download from the Community Modeling and Analysis System website: http://www.cmascenter.org/

  Meteorological models: http://www.mmm.ucar.edu/mm5/
  http://www.wrf-model.org/index.php
  
  modelcontactinfo :Rohit Mathur, Atmospheric Modeling Division, NERL/ORD, mathur.rohit@epa.gov, (919) 541-1483 Developer Contact

  Rohit Mathur, Atmospheric Modeling Division, NERL/ORD, mathur.rohit@epa.gov, (919) 541-1483

  Jonathan Pleim, Atmospheric Modeling Division, NERL/ORD, pleim.jon@epa.gov, (919) 541-1336

  Shawn Roselle, Atmospheric Modeling Division, NERL/ORD, roselle.shawn@epa.gov, (919) 541-7699

  Kenneth Schere, Atmospheric Modeling Division, NERL/ORD, schere.kenneth@epa.gov, (919) 541-3795
  
  Model Inputs :Hourly (or finer temporal resolution) gridded meteorological data from either MM5 or WRF meteorological model; processed through CMAQ’s Meteorology-Chemistry Interface Processor (MCIP)

  Hourly (or finer temporal resolution) gridded Emissions data from SMOKE emissions modeling system (including biogenic and anthropogenic source emissions of CO, NO, NO2, VOCs, SO2, NH3, and particulate matter)

  Initial gridded chemical concentrations and hourly or static lateral boundary concentrations
  
  Model Outputs :Hourly three-dimensional grid of estimated air trace gas concentrations (e.g., ozone, NO, NO2), and fine particulate matter (PM2.5 and its size-distributed chemical constituents). Hourly two-dimensional gridded wet and dry deposition amounts of chemical species, and gridded atmospheric visibility. Temporal resolution of output can be defined by user.
  
  

  Model Computer Requirements:

  Model Operating Systems Needs :RedHat Linux, IBM AIX (Unix), for example
  
  Model Hardware Needs :Unix/Linux platform (single processor, or multi-processor), 2 Ghz chip speed or better, 1Gb memory per processor; Unix/Linux clusters (8 CPUs is typical); or IBM-SP supercomputer
  
  Model Programming Language(s) :FORTRAN90, C++
  
  other_req :netCDF, IOAPI libraries