EPA Science Inventory

Diagnostic Analysis of Ozone Concentrations Simulated by Two Regional-Scale Air Quality Models

Citation:

HERWEHE, J., T. L. OTTE, R. MATHUR, AND S. T. RAO. Diagnostic Analysis of Ozone Concentrations Simulated by Two Regional-Scale Air Quality Models. ATMOSPHERIC ENVIRONMENT. Elsevier Science Ltd, New York, NY, 45(33):5957-6106, (2011).

Description:

Since the Community Multiscale Air Quality modeling system (CMAQ) and the Weather Research and Forecasting with Chemistry model (WRF/Chem) use different approaches to simulate the interaction of meteorology and chemistry, this study compares the CMAQ and WRF/Chem air quality simulation results for a month-long retrospective study period (August 2006) over the eastern United States, including comparisons with data from several observation networks. To help improve the comparability of the two models, the 2005 Carbon Bond chemical mechanism (CB05) was implemented into WRF/Chem. In addition, the same emissions, initial and boundary conditions have been used in both models to inter-compare simulated ozone (O3) from the WRF-driven CMAQ and WRF/Chem models. Results reveal that ground-level O3 from both models is biased high, especially in the central South and Ohio River Valley; however, WRF/Chem predicts roughly 10% more O3 aloft (1000-2500 m AGL) than CMAQ. Different model configurations due to the choice of land surface model (LSM), planetary boundary layer (PBL) physics scheme, and convective cloud parameterization contributed to the differences seen in simulated O3, but most important were the different treatments of the radiative effects of clouds by their respective photolysis schemes.

Purpose/Objective:

The National Exposure Research Laboratory′s (NERL′s) Atmospheric Modeling and Analysis Division (AMAD) conducts research in support of EPA′s mission to protect human health and the environment. AMAD′s research program is engaged in developing and evaluating predictive atmospheric models on all spatial and temporal scales for forecasting the Nation′s air quality and for assessing changes in air quality and air pollutant exposures, as affected by changes in ecosystem management and regulatory decisions. AMAD is responsible for providing a sound scientific and technical basis for regulatory policies based on air quality models to improve ambient air quality. The models developed by AMAD are being used by EPA, NOAA, and the air pollution community in understanding and forecasting not only the magnitude of the air pollution problem, but also in developing emission control policies and regulations for air quality improvements.

URLs/Downloads:

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Diagnostic Analysis of Ozone Concentrations Simulated by Two Regional-Scale Air Quality Models   (PDF,NA pp, 9166 KB,  about PDF)

Record Details:

Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Start Date: 10/10/2011
Completion Date: 10/10/2011
Record Last Revised: 09/06/2011
Record Created: 04/12/2011
Record Released: 04/12/2011
OMB Category: Other
Record ID: 234743

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL EXPOSURE RESEARCH LAB

ATMOSPHERIC MODELING AND ANALYSIS DIVISION

APPLIED MODELING BRANCH