Wind Modeling in Support of Transport and Dispersion
General Transport and Dispersion Modeling
In general, air quality models are used to predict levels of pollutants or hazards in the atmosphere to determine their effect on visibility and human health as well as understand historical pollution problems.
By running the models for historical pollution events, it can be determined whether the physics and chemistry are properly captured in the model, its emission inventory, and in the modeled meteorology. If comparisons are realistic, then predictions as to future conditions of Air Quality can be made for a specific site.
If the comparisons are unrealistic, future research is needed to aid in developing more realistic physics and chemistry. The speed of computers is such that daily air quality predictions can be made to to determine the Air Quality Index (AQI) which determines visibility and health impact. In addition analysis of the transport can lead to physical insight as to the nature of the problem.
We can aid in all of these situations and some example projects are shown below.
Modeling includes computer running under the LINUX platform
to run photochemical grid models such as CAMx (Comprehensive Air Quality
Modeling with Extensions), UAM-V (Urban Airshed Model V), MAQSIP (Multi-scale
Air Quality Simulation Platform), and CMAQ (Community Multi-scale Air
These models are used to
predict ozone formation, study historical ozone events and further develop
Real-Time Photochemical Ozone/Smog Predictions for California's Central Valley
of Ozone/Smog Formation in
NARSTO Model Comparisons
Power Plant Effects on the UAM Modeling Domain of Pima County, Arizona
Trajectory Analysis of
Transport Leading to Rapid Ozone
Formation in Houston
Trajectory Analysis of Transport from the Central Valley to
the LA Basin
Monitoring Sites are numbered and were investigated based on rapid ozone formation. In this case pre-cursor chemicals to Ozone formation are originating in Houston's ship channel.
Research and Project Activities:
Computers running under Windows have
been used to run CALMET/CALPUFF model and AERMOD for fugitive dust and other
Computers running under the LINUX
platform run PM10 and PM 2.5 regional models such as CAMx for PM (Comprehensive Air
Quality Modeling with Extensions) and UAM-AERO (Urban Airshed Model for
In addition, research activities
have been done to develop microscale/turbulent models to understand the
transport of aerosols, dust, and other agents.
Eta-CALMET-CALPUFF analysis was performed using the Coloraod Department of Public Health and Environment (CDPHE) suggested protocol for modeling BART elgibile sites that may affect Class I Federal Lands. Preliminary results showed that Eta-CALMET wind fields predict a similar number of poor visibility days similar to that using MM5-CALMET analysis and observations for the input winds. The overall objective of this study was to compare the results of two modeling methodologies for assessing visibility impacts in Class I Areas, and determine the possibility of using the “new” method effectively for this type of study. The CEMEX cement plant near Lyons, CO was used as a case study using the suggested emission rates provide by CDHPE.
Figure 1. Class I areas within 50 and 300 kilometers of the BART-eligible source.
Figure 2. A sample of hourly predicted winds during 365 days of simulation for 2002
Table 1. The maximum deciview change during the 2002 simulation.
Table 2. The 8th highest deciview change along with the number of days there is a 0.5 dv change due to the source in the 2002 simulation.
At the University of Colorado at Colorado Springs (UCCS), Dr. Jason Roney was funded to develop a series of real time model prediction capabilities for potential threats from terrorist activities as part of the NISSC program. Using NCEP Eta and EDAS weather models that were coupled to the CALMET/CALPUFF transport and disperions model, Dr. Roney developed a real-time capability in which the daily Eta forecast was used to predict transport and dispersion of fictional release events. Eventually, this modeling technique led to performing an analysis of potential nuclear power plant threats caused by accident or terrorist activity along the US-Canada border. For this proto-type analysis, some worst-case scenario days were chosen based on wind directions that would potentially blow the contaminants towards large population centers. In the process, different atmospheric stability classes were tested as well, but the main focus was on directionality of the wind and quick analysis. All values in this analysis were notional based on educational guesses based on the existing literature.
J. Roney, N.J. Wheeler. Impact of emissions from a proposed Arizona clean fuels facility on UAM-IV predicted ozone concentrations in the Maricopa County ozone nonattainment area. Final report prepared for URS Corporation, Phoenix, AZ by Sonoma Technology, Inc., Petaluma, CA, STI-901520-2206-FR, June, 2002.
S.G. Brown S.G., P.T. Roberts, J.A. Roney, and N.P. Hyslop, “Preliminary analyses of 2001 event-triggered VOC and carbonyl samples”. Interim report prepared for Texas Natural Resource Conservation Commission, Austin, TX by Sonoma Technology, Inc., Petaluma, CA, STI-900680-2188-IR, June, 2001.
N.J.M. Wheeler and J. Roney, “NARSTO model inter-comparison (NMI) study”, Report prepared for Texas Natural Resource Conservation Commission, Austin, TX by Sonoma Technology, Inc., Petaluma, CA, STI-900560-2111-DD, August, 2001.
P.T. Roberts, S.G. Brown, H.H. Main , M.P. Buhr, N.P. Hyslop , C.P. MacDonald , J. Roney, C.A. Knoderer, D. Miller, “Preliminary VOC, olefin, and conceptual model results for Houston”, Presented to the Texas Natural Resource Conservation Commission, Austin, TX April 4, 2002.
N.J.M. Wheeler, F.W. Lurmann, P.A., Ryan , J.A. Roney, P.T. Roberts, C.P. MacDonald C.P, L.R., Chinkin, D.L. Coe D.L, S. Hanna S, N. Seaman, G. Hunter , D. Scalfano, “The SO2 and NO2 increment analysis for the Breton National Wilderness Area”, Presented to the Minerals Management Service and Scientific Review Board, New Orleans, Louisiana, December 13, STI-901369-2135, 2001.