A tracer study of pollutant transport and dispersion in the Los Angeles area

Drivas, Peter; Shair, F. H.

doi:10.1016/0004-6981(74)90049-3

Cited by 35 publications

(12 citation statements)

References 32 publications

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“…SF 6 is widely used as an electrical insulating gas in various high-voltage electrical and electronic equipment such as circuit breakers, capacitors, transformers, and microwave components because of its high chemical stability and its ability to impede electric breakdown [e.g., Brown, 1966]. Because sulfur hexafluoride can be measured in situ at a level of 1 part of SF 6 in 10 TM parts of air [Clemons et al, 1968], SF 6 has also been used as a meteorological tracer [e.g., Turk et al, 1968;Drivas and Shair, 1974] and was one of the first trace species detected in the stratosphere using gas chromatographic separation and electron capture detectors [Krey et al, 1977a, b]. The atmospheric lifetime of SF 6 may be very long, since there are no known sinks in the troposphere, and SF 6 is transparent to UV photolysis in the stratosphere [Singh et al, 1977[Singh et al, , 1979.…”

Section: Introductionmentioning

confidence: 66%

Infrared spectroscopic detection of sulfur hexafluoride (sf₆) in the lower stratosphere and upper troposphere

Rinsland

Brown²,

Farmer

1990

J. Geophys. Res.

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Absorption by sulfur hexafluoride (SF6) has been detected in high‐resolution infrared solar spectra of the lower stratosphere and upper troposphere. The identification is based on measurements of the intense, unresolved ν3 band Q branch at 947.9 cm−1 in solar occultation spectra recorded near 31°N and 47°S latitude by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer on April 30 to May 1, 1985, during the Spacelab 3 shuttle mission. Vertical SF6 volume mixing ratio profiles have been retrieved using an onion‐peeling nonlinear least squares spectral fitting procedure with SF6 line‐by‐line Spectroscopic parameters generated recently by Bobin and coworkers from their analysis of the SF6 ν3 band. Between 12 and 18 km altitude, the region over which the retrievals are most accurate (about ±26% one sigma), the SF6 volume mixing ratio is independent of altitude with an average measured value of 1.42 parts per trillion by volume (pptv) at 31°N latitude. There is evidence for a decline in the SF6 volume mixing ratio with increasing altitude between 18 and 22 km, but the results are not conclusive because of the weakness of the absorption. Absorption by the SF6 Q branch is below the noise level of the spectra at tangent heights above ∼22 km. The measurements are compared with previously reported values and discussed in terms of the atmospheric lifetime of SF6, the long‐term trend of atmospheric SF6, and the possible role of SF6 as an atmospheric greenhouse gas.

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Section: Introductionmentioning

confidence: 66%

Infrared spectroscopic detection of sulfur hexafluoride (sf₆) in the lower stratosphere and upper troposphere

Rinsland

Brown²,

Farmer

1990

J. Geophys. Res.

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“…This information may also be considered by civil engineers which work on planning the city, particularly on the layout of buildings and roads. Finally, the results of this study may help engineers developing ventilation systems for neighboring buildings to optimize the location and design of HVAC inlets and outlets (Drivas and Shair, 1974).…”

Section: Introductionmentioning

confidence: 94%

CFD Simulation of the Dispersion of Exhaust Gases in a Traffic Loaded Street of Astana, Kazakhstan

Akhatova

Kassymov

Kazmaganbetova

et al. 2016

J. Urb. and Environ. Engng

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Abstract:The aim of this paper is to consider one of the most traffic-loaded regions of Astana city (Kazakhstan) and to determine the concentration of carbon-monoxide (CO) in the air during the peak hours. CFD analysis based on the SolidWorks-EFD platform was used to simulate the dispersion of contaminants given the estimated emission rates and weather conditions at the crossroad of Bogenbay Batyr and Zhenis Avenues in Astana.Turbulence prediction was based on k-ε model with wall functions. The governing equations were discretized using the finite volume method and a 2 nd order spatial scheme. The mesh verification was based on 1% convergence criterion for a 50% of mesh density increment; air pressure near the wall of a selected building was chosen as the parameter to control the convergence. Numerical results are presented for prevailing conditions during all 4 seasons of the year, demonstrating that the highest levels of CO are recorded in summer and reach the values up to 11.2 ppm which are still lower than the maximum level admitted for humans. Nevertheless, obtained results show that Astana is gradually becoming a city that is likely to reach the critical levels of pollutants in the nearest future if control measures are not taken with enough anticipation. As for a future work, it is proposed to perform in-situ validation of specific scenarios to check and support the results obtained with CFD and to develop then specific policies for tackling the problem before it becomes evident.

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“…5 A review of turbulent diffusion typing schemes has been prepared by Gifford 6 and a comparison of hourly predicted stability classes for a one-year period was reported by Sedefian and Bennett. 7 …”

Section: Discussionmentioning

confidence: 99%

Wind Shear Effects on Air Column Trajectories in Urban Air Pollution Models

Chang

Norbeck

1983

Journal of the Air Pollution Control Association

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A tracer study of pollutant transport and dispersion in the Los Angeles area

Cited by 35 publications

References 32 publications

Infrared spectroscopic detection of sulfur hexafluoride (sf₆) in the lower stratosphere and upper troposphere

Infrared spectroscopic detection of sulfur hexafluoride (sf₆) in the lower stratosphere and upper troposphere

CFD Simulation of the Dispersion of Exhaust Gases in a Traffic Loaded Street of Astana, Kazakhstan

Wind Shear Effects on Air Column Trajectories in Urban Air Pollution Models

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A tracer study of pollutant transport and dispersion in the Los Angeles area

Cited by 35 publications

References 32 publications

Infrared spectroscopic detection of sulfur hexafluoride (sf6) in the lower stratosphere and upper troposphere

Infrared spectroscopic detection of sulfur hexafluoride (sf6) in the lower stratosphere and upper troposphere

CFD Simulation of the Dispersion of Exhaust Gases in a Traffic Loaded Street of Astana, Kazakhstan

Wind Shear Effects on Air Column Trajectories in Urban Air Pollution Models

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Infrared spectroscopic detection of sulfur hexafluoride (sf₆) in the lower stratosphere and upper troposphere

Infrared spectroscopic detection of sulfur hexafluoride (sf₆) in the lower stratosphere and upper troposphere