Models, Tools and Databases for Air Research


  • AERMOD Modeling System
    A steady-state plume model that incorporates air dispersion based on planetary boundary layer turbulence structure and scaling concepts, including treatment of both surface and elevated sources, and both simple and complex terrain.
  • Community Multi-scale Air Quality (CMAQ) Model
    CMAQ is an air quality model and software suite designed to model multiple pollutants at multiple scales. CMAQ allows regulatory agencies and state governments to evaluate the impact of air quality management decisions, and gives scientists the ability to probe, simulate, and understand chemical and physical interactions in the atmosphere.
  • Community-LINE Source (C-LINE) Model
    C-LINE is a web-based model that estimates emissions and dispersion of toxic air pollutants for roadways in the U.S. C-LINE is intended to support local communities and planners to get an initial assessment of near-source air quality impacts of transportation-related sources using national-scale input databases, and reduced-form modeling approaches.
  • EPAUS9R - An Energy Systems Database for use with the Market Allocation (MARKAL) Model
    The EPAUS9r is a regional database representation of the United States energy system. The database uses the MARKAL model. MARKAL is an energy system optimization model used by local and federal governments, national and international communities and academia. EPAUS9r represents energy supply, technology, and demand throughout the major sectors of the U.S. energy system.
  • Downscaler Model 
    The Downscaler Model combines daily ozone and particulate matter monitoring and modeling data from across the U.S. to provide improved fine-scale predictions of air quality in communities and other specific locales. 
    GLIMPSE is a tool to find US policy scenarios that simultaneously improve air quality human health, reduce impacts to ecosystems, and mitigate climate change. It is designed to be fast -- to allow decision-makers to explore a range of options, as well as comprehensive -- to avoid unintended consequences.
  • Microenvironment Tracker (MicroTrac)
    Microenvironment Tracker (MicroTrac) is a model that uses global positioning system (GPS) data to estimate time of day and duration that people spend in different microenvironments (e.g., indoors and outdoors at home, work, school).
  • Positive Matrix Factorization 5.0 (EPA PMF 5.0)
  • EPA PMF is a receptor model developed and distributed by ORD. The model uses ambient measurements (water, air, sediments) and estimated uncertainties in those measurements to infer emission sources types impacting samples and their contribution to the sample.
  • Unmix 6.0
    Unmix is a receptor model that is distributed by ORD. The model uses ambient measurements to determine the number of source types and their impacts at a monitoring site. The Unmix algorithm is based on defining feasible solution space for the input data. This space is derived using edges or sample groups with relatively low impacts. These edges define source types which account for the majority of variability in the data.


  • Atmospheric Model Evaluation Tool (AMET)
    AMET helps in the evaluation of meteorological and air quality simulations.
  • BenMAP
    BenMAP is a Windows-based computer program that uses a Geographic Information System (GIS)-based to estimate the health impacts and economic benefits occurring when populations experience changes in air quality.
  • EPA Air Sensor Toolbox for Citizen Scientists
    EPA's Air Sensor Toolbox for Citizen Scientists provides information and guidance on new low-cost compact technologies for measuring air quality. Citizens are interested in learning more about local air quality where they live, work and play. EPA's Toolbox includes information about: Sampling methodologies; Calibration and validation approaches; Measurement methods options; Data interpretation guidelines; Education and outreach; and Low cost sensor performance information.
  • Federal Reference & Federal Equivalency Methods
    EPA scientists develop and evaluate Federal Reference Methods and Federal Equivalency Methods for accurately and reliably measuring six primary air pollutants in outdoor air. These methods are used by states and other organizations to assess implementation actions needed to attain National Ambient Air Quality Standards.
  • Fertilizer Emission Scenario Tool for CMAQ (FEST-C)
    FEST-C facilitates the definition and simulation of new cropland farm management system scenarios or editing of existing scenarios to drive Environmental Policy Integrated Climate model (EPIC) simulations.  For the standard 12km continental Community Multi-Scale Air Quality model (CMAQ) domain, this amounts to about 250,000 simulations for the U.S. alone. It also produces gridded daily EPIC weather input files from existing hourly Meteorology-Chemistry Interface Processor (MCIP) files, transforms EPIC output files to CMAQ-ready input files and links directly to Visual Environment for Rich Data Interpretation (VERDI) for spatial visualization of input and output files. The December 2012 release will perform all these functions for any CMAQ grid scale or domain.
  • Indoor Semi-Volatile Organic Compound (i-SVOC)
    i-SVOC Version 1.0 is a general-purpose software application for dynamic modeling of the emission, transport, sorption, and distribution of semi-volatile organic compounds (SVOCs) in indoor environments. i-SVOC supports a variety of uses, including exposure assessment and the evaluation of mitigation options. SVOCs are a diverse group of organic chemicals that can be found in:
    • Pesticides;
    • Ingredients in cleaning agents and personal care products;
    • Additives to vinyl flooring, furniture, clothing, cookware, food packaging, and electronics.
    Many are also present in indoor air, where they tend to bind to interior surfaces and particulate matter (dust).
  • Optical Noise-Reduction Averaging (ONA) Program Improves Black Carbon Particle Measurements Using Aethalometers
    ONA is a program that reduces noise in real-time black carbon data obtained using Aethalometers. Aethalometers optically measure the concentration of light absorbing or “black” particles that accumulate on a filter as air flows through it. These particles are produced by incomplete fossil fuel, biofuel and biomass combustion. Under polluted conditions, they appear as smoke or haze.
  • RETIGO tool
    Real Time Geospatial Data Viewer (RETIGO) is a free, web-based tool that shows air quality data that are collected while in motion (walking, biking or in a vehicle). The tool helps users overcome technical barriers to exploring air quality data. After collecting measurements, citizen scientists and other users can import their own data and explore the data on a map.
  • Remote Sensing Information Gateway (RSIG)
    RSIG offers a new way for users to get the multi-terabyte, environmental datasets they want via an interactive, Web browser-based application. A file download and parsing process that now takes months will be reduced via RSIG to minutes.
  • Simulation Tool Kit for Indoor Air Quality and Inhalation Exposure (IAQX)
    IAQX version 1.1 is an indoor air quality (IAQ) simulation software package that complements and supplements existing indoor air quality simulation (IAQ) programs. IAQX is for advanced users who have experience with exposure estimation, pollution control, risk assessment, and risk management. There are many sources of indoor air pollution, such as building materials, furnishings, and chemical cleaners. Since most people spend a large portion of their time indoors, it is important to be able to estimate exposure to these pollutants. IAQX helps users analyze the impact of pollutant sources and sinks, ventilation, and air cleaners. It performs conventional IAQ simulations to calculate the pollutant concentration and/or personal exposure as a function of time. It can also estimate adequate ventilation rates based on user-provided air quality criteria. This is a unique feature useful for product stewardship and risk management.
  • Spatial Allocator
    The Spatial Allocator provides tools that could be used by the air quality modeling community to perform commonly needed spatial tasks without requiring the use of a commercial Geographic Information System (GIS).
  • Traceability Protocol for Assay and Certification of Gaseous Calibration Standards
    This is used to certify calibration gases for ambient and continuous emission monitors. It specifies methods for assaying gases and establishing traceability to National Institute of Standards and Technology (NIST) reference standards. Traceability is required under EPA ambient and continuous emission monitoring regulations.
  • Watershed Deposition Mapping Tool (WDT)
    WDT provides an easy to use tool for mapping the deposition estimates from CMAQ to watersheds to provide the linkage of air and water needed for TMDL (Total Maximum Daily Load) and related nonpoint-source watershed analyses.
  • Visual Environment for Rich Data Interpretation (VERDI)
    VERDI is a flexible, modular, Java-based program for visualizing multivariate gridded meteorology, emissions, and air quality modeling data created by environmental modeling systems such as CMAQ and the Weather Research and Forecasting (WRF) model.