• Byun, D. W., and K. Schere, 2006: Review of the governing equations, computational algorithms, and other components of the models-3 Community Multiscale Air Quality (CMAQ) modeling system. Appl. Mech. Rev., 59 , 5177.

    • Search Google Scholar
    • Export Citation
  • Ching, J., T. Pierce, T. Palma, W. Hutzell, R. Tang, A. Cimorelli, and J. Herwehe, 2004: Linking air toxic concentrations from CMAQ to the HAPEM5 exposure model at neighborhood scales for the Philadelphia area. Preprints, Fifth Symp. on the Urban Environment, Vancouver, BC, Canada, Amer. Meteor. Soc., CD-ROM, J4.4.

  • Ching, J., J. Herwehe, and J. Swall, 2006a: On joint deterministic grid modeling and sub grid variability conceptual framework for model evaluation. Atmos. Environ., 40 , 49364945.

    • Search Google Scholar
    • Export Citation
  • Ching, J., V. Isakov, M. Majeed, and J. S. Irwin, 2006b: An approach for incorporating sub-grid variability information into air quality. Preprints, 14th Joint Conf. on the Applications of Air Pollution Meteorology, Atlanta, GA, Amer. Meteor. Soc., CD-ROM, 2.1.

  • Cimorelli, A. J., and Coauthors, 2005: AERMOD: A dispersion model for industrial source applications. Part I: General model formulation and boundary layer characterization. J. Appl. Meteor., 44 , 682693.

    • Search Google Scholar
    • Export Citation
  • Georgopoulos, P. G., and P. J. Lioy, 2006: From theoretical aspects of human exposure and dose assessment to computational model implementation: The Modeling Environment for Total Risk studies (MENTOR). J. Toxicol. Environ. Health, 9B , 457483.

    • Search Google Scholar
    • Export Citation
  • Graham, S. E., and J. M. Burke, 2003: Microenvironmental exposures to benzene: A critical review and probabilistic model input distribution development. Environmental Protection Agency Rep. EPA/600/J-03/008, Office of Research and Development, Research Triangle Park, NC, 54 pp.

  • Grell, G. A., J. Dudhia, and D. R. Stauffer, 1995: A description of the fifth-generation Penn State/NCAR Mesoscale Model (MM5). NCAR Tech. Note NCAR/TN-398, 122 pp.

  • Herwehe, J. A., 2000: A numerical study of the effects of large eddies on the trace gas measurements and photochemistry in the convective boundary layer. Ph.D. dissertation, University of Alabama in Huntsville, 242 pp. [Available from University of Alabama in Huntsville, Atmospheric Science Department, Huntsville, AL 35899.].

  • Herwehe, J. A., J. K. S. Ching, and J. Swall, 2004: Quantifying subgrid pollutant variability in Eulerian air quality models. Preprints, 13th Conf. on the Applications of Air Pollution Meteorology with the Air & Waste Management Association, Vancouver, BC, Canada, Amer. Meteor. Soc., CD-ROM, 7.5.

  • Isakov, V., and A. Venkatram, 2006: Resolving neighborhood scale in air toxics modeling: A case study in Wilmington, California. J. Air Waste Manage. Assoc., 56 , 559568.

    • Search Google Scholar
    • Export Citation
  • Jerrett, M., A. Arain, P. Kanaroglou, B. Becjerman, D. Potoglou, T. Sahsuvaroglu, J. Morrison, and C. Giovis, 2005: A review and evaluation of intraurban air pollution exposure models. J. Expo. Anal. Environ. Epidemiol., 15 , 185204.

    • Search Google Scholar
    • Export Citation
  • Karamchandani, P., C. Seigneur, K. Vijayaraghavan, and S-Y. Wu, 2002: Development and application of a state-of-the-science plume-in-grid model. J. Geophys. Res., 107 .4403, doi:10.1029/2002JD002123.

    • Search Google Scholar
    • Export Citation
  • Luecken, D. J., W. T. Hutzell, and G. J. Gipson, 2006: Development and analysis of air quality modeling simulations for hazardous air pollutants. Atmos. Environ., 40 , 50875096.

    • Search Google Scholar
    • Export Citation
  • Lumley, J. L., and H. A. Panofsky, 1964: The Structure of Atmospheric Turbulence. Monographs and Texts in Physics and Astronomy, Vol. 12, Interscience, 239 pp.

  • Miao, J. F., D. Chen, and K. Wyser, 2006: Modelling subgrid scale dry deposition velocity of O3 over the Swedish west coast with MM5-PX model. Atmos. Environ., 40 , 415429.

    • Search Google Scholar
    • Export Citation
  • Odman, M. T., and A. G. Russell, 1991: Multiscale modeling of pollutant transport and chemistry. J. Geophys. Res., 96 , 73637370.

  • Spicer, C. W., and Coauthors, 1996: Variability of hazardous air pollutants in an urban area. Atmos. Environ., 30 , 34433456.

  • Touma, J. S., V. Isakov, J. Ching, and C. Seigneur, 2006: Air quality modeling of hazardous pollutants: Current status and future directions. J. Air Waste Manage. Assoc., 56 , 547558.

    • Search Google Scholar
    • Export Citation
  • U.S. Environmental Protection Agency, 1995: User’s guide for the Industrial Source Complex (ISC3) dispersion models Office of Air Quality Planning and Standards Rep. EPA-454/B-95-003b, Vol. 2, Office of Air Quality Planning and Standards, Research Triangle Park, NC, 120 pp.

  • U.S. Environmental Protection Agency, 2000: User’s guide for the Assessment System for Population Exposure Nationwide (ASPEN, version 1.1) Model. Office of Air Quality Planning and Standards Rep. EPA-454/R-00-017, 108 pp.

  • U.S. Environmental Protection Agency, cited. 2004: 1999 national emission inventory documentation and data—Final version 3.0. [Available online at http://www.epa.gov/ttn/chief/net/.].

  • U.S. Environmental Protection Agency, cited. 2005: Human exposure modeling—Hazardous Air Pollutant Exposure Model (HAPEM). [Available online at http://www.epa.gov/ttn/fera/human_hapem.html.].

  • Weijers, E. P., A. Y. Khlystov, G. P. A. Kos, and J. W. Erisman, 2004: Variability of particulate matter concentrations along roads and motorways determined by a moving measurement unit. Atmos. Environ., 38 , 29933002.

    • Search Google Scholar
    • Export Citation
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Using CMAQ for Exposure Modeling and Characterizing the Subgrid Variability for Exposure Estimates

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  • 1 NOAA/Atmospheric Sciences Modeling Division, Research Triangle Park, North Carolina
  • | 2 John S. Irwin and Associates, Raleigh, North Carolina
  • | 3 NOAA/Atmospheric Sciences Modeling Division, Research Triangle Park, North Carolina
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Abstract

Atmospheric processes and the associated transport and dispersion of atmospheric pollutants are known to be highly variable in time and space. Current air-quality models that characterize atmospheric chemistry effects, for example, the Community Multiscale Air Quality model (CMAQ), provide volume-averaged concentration values for each grid cell in the modeling domain given the stated conditions. Given the assumptions made and the limited set of processes included in any model’s implementation, there are many sources of “unresolved” subgrid variability. This raises the question of the importance of the unresolved subgrid variations on exposure assessment results if such models were to be used to assess air toxics exposure. In this study, the Hazardous Air Pollutant Exposure Model (HAPEM) is applied to estimate benzene and formaldehyde inhalation exposure using ambient annually averaged concentrations predicted by CMAQ to investigate how within-grid variability can affect exposure estimates. An urban plume dispersion model was used to estimate the subgrid variability of annually averaged benzene concentration values within CMAQ grid cells for a modeling domain centered on Philadelphia, Pennsylvania. Significant (greater than a factor of 2) increases in maximum exposure impacts were seen in the exposure estimates in comparison with exposure estimates generated using CMAQ grid-averaged concentration values. These results consider only one source of subgrid variability, namely, the discrete location and distribution of emissions, but they do suggest the importance and value of developing improved characterizations of subgrid concentration variability for use in air toxics exposure assessments.

* Additional affiliation: U.S. Environmental Protection Agency, Research Triangle Park, North Carolina

Corresponding author address: Vlad Isakov, U.S. Environmental Protection Agency, AMD/NERL, 109 TW Alexander Dr, Research Triangle Park, NC 27709. Email: isakov.vlad@epa.gov

This article included in the NOAA/EPA Golden Jubilee special collection.

Abstract

Atmospheric processes and the associated transport and dispersion of atmospheric pollutants are known to be highly variable in time and space. Current air-quality models that characterize atmospheric chemistry effects, for example, the Community Multiscale Air Quality model (CMAQ), provide volume-averaged concentration values for each grid cell in the modeling domain given the stated conditions. Given the assumptions made and the limited set of processes included in any model’s implementation, there are many sources of “unresolved” subgrid variability. This raises the question of the importance of the unresolved subgrid variations on exposure assessment results if such models were to be used to assess air toxics exposure. In this study, the Hazardous Air Pollutant Exposure Model (HAPEM) is applied to estimate benzene and formaldehyde inhalation exposure using ambient annually averaged concentrations predicted by CMAQ to investigate how within-grid variability can affect exposure estimates. An urban plume dispersion model was used to estimate the subgrid variability of annually averaged benzene concentration values within CMAQ grid cells for a modeling domain centered on Philadelphia, Pennsylvania. Significant (greater than a factor of 2) increases in maximum exposure impacts were seen in the exposure estimates in comparison with exposure estimates generated using CMAQ grid-averaged concentration values. These results consider only one source of subgrid variability, namely, the discrete location and distribution of emissions, but they do suggest the importance and value of developing improved characterizations of subgrid concentration variability for use in air toxics exposure assessments.

* Additional affiliation: U.S. Environmental Protection Agency, Research Triangle Park, North Carolina

Corresponding author address: Vlad Isakov, U.S. Environmental Protection Agency, AMD/NERL, 109 TW Alexander Dr, Research Triangle Park, NC 27709. Email: isakov.vlad@epa.gov

This article included in the NOAA/EPA Golden Jubilee special collection.

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