A regional scale model for ozone in the United States with subgrid representation of urban and power plant plumes
- Harvard Univ., Cambridge, MA (United States)
A new approach to modeling regional air chemistry is presented for application to industrialized regions such as the continental US. Rural chemistry and transport are simulated using a coarse grid, while chemistry and transport in urban and power plant plumes are represented by detailed subgrid models. Emissions from urban and power plant sources are processed in generalized plumes where chemistry and dilution proceed for 8-12 hours before mixing with air in a large resolution element. A realistic fraction of pollutants reacts under high-NO{sub x} conditions, and NO{sub x} is removed significantly before dispersal. Results from this model are compared with results from grid odels that do not distinguish plumes and with observational data defining regional ozone distributions. Grid models with coarse resolution are found to artificially disperse NO{sub x} over rural areas, therefore overestimating rural levels of both NO{sub x} and O{sub 3}. Regional net ozone production is too high in coarse grid models, because production of O{sub 3} is more efficient per molecule of NO{sub x} in the low-concentration regime of rural areas than in heavily polluted plumes from major emission sources. Ozone levels simulated by this model are shown to agree with observations in urban plumes and in rural regions. The model reproduces accurately average regional and peak ozone concentrations observed during a 4-day ozone episode. Computational costs for the model are reduced 25-to 100-fold as compared to fine-mesh models.
- OSTI ID:
- 5081259
- Journal Information:
- Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 95:D5; ISSN 0148-0227; ISSN JGREA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
200500* -- Fossil-Fueled Power Plants-- Environmental Aspects-- (1990-)
54 ENVIRONMENTAL SCIENCES
540120 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
AIR POLLUTION
AIR QUALITY
ATMOSPHERIC CHEMISTRY
CHALCOGENIDES
CHEMISTRY
DEVELOPED COUNTRIES
DILUTION
ECOLOGICAL CONCENTRATION
EMISSION
ENVIRONMENTAL QUALITY
ENVIRONMENTAL TRANSPORT
GENERAL CIRCULATION MODELS
MASS TRANSFER
MATHEMATICAL MODELS
MIXING
NITROGEN COMPOUNDS
NITROGEN OXIDES
NORTH AMERICA
OXIDES
OXYGEN COMPOUNDS
OZONE
PLUMES
POLLUTION
POWER PLANTS
REGIONAL ANALYSIS
RURAL AREAS
URBAN AREAS
USA