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EPA Air Research

Methods, Models, Tools and Databases

  • 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 Modeling and Analysis System (CMAS)
    The CMAS Center has two main goals:
    • To improve environmental managers' ability to evaluate the impact of air quality management strategies for multiple pollutants at multiple scales (local, regional, national), and
    • To improve scientists' ability to probe, understand, and simulate chemical and physical pollutant interactions in the atmosphere
  • 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.
    • CMAQ Aerosol Module
      CMAQ version 5.0 includes a complete redesign of the aerosol module eliminating unnecessary dependencies and duplications across modules
    • CMAQ for Air Toxics and Multipollutant Modeling
      In the past, chemical mechanism and air quality development have focused on Criteria Air Pollutants (CAPs) such as ozone and primary inorganic particulate matter. CMAQ also has the capacity to predict concentration and deposition of many Hazardous Air Pollutants (HAPs) or air toxics.
  • Exposure Model for Individuals (EMI)
    The EMI is an air pollution exposure model for individuals in cohort health studies. The EMI is being developed to predict individual exposures for multiple air pollutants from ambient concentrations, meteorology, and questionnaire information such as building characteristics, occupant behavior related to building operation, and time-activity patterns. The overall goal of this research is to provide a modeling tool to enhance the ability to conduct air pollution human exposure assessments with greater certainty.
  • Positive Matrix Factorization 3.0 (EPA PMF 3.0) 
    EPA PMF is a receptor model developed and distributed by ORD. The model uses ambient measurements and estimated uncertainties in those measurements to infer emission sources likely impacting a monitor and by how much. The solution is based on a constrained weighted least squares approach.
  • 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.

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  • Atmospheric Model Evaluation Tool (AMET)
    AMET helps in the evaluation of meteorological and air quality simulations.
  • 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.  The interface will be released through CMAS.
  • Integrated Tools for Scenario Discovery: GLIMPSE
    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.
  • 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.
  • 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).
  • 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.

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  • Fused Air Quality Surfaces Using Downscaling
    This database provides access to the most recent O3 and PM2.5 surfaces datasets using downscaling.
  • Fused Discrete Air Quality Surfaces
    This database provides access to discrete, daily O3 and PM2.5 predictive surfaces. Here, a space-time hierachical Bayesian model is used to fuse daily ozone (8-hr maximum) monitoring data from the National Air Monitoring Stations/State and Local Air Monitoring Stations (NAMS/SLAMS) with gridded output from the Models-3/CMAQ.
  • SPECIATE 4.3 Database
    SPECIATE is a repository of volatile organic gas and particulate matter (PM) speciation profiles of air pollution sources.
  • Watershed Deposition Tool Data
    This is a database of deposition components available from CMAQ.

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