Effects of Constant<i>versus</i>Diurnally-Varying Light Intensity on Ozone Formation

Darnall, Karen R.; Atkinson, Roger; Winer, Arthur M.; Pitts, James N.

doi:10.1080/00022470.1981.10465221

Cited by 6 publications

(4 citation statements)

References 3 publications

(3 reference statements)

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“…Irradiation was provided to two diametrically opposed banks of 40 Sylvania 40-W BL lamps, backed by arrays of Alzak-coated reflectors. The light intensity in the chamber was controlled by switching off sets of lights as previously described [17], and the light intensities for the various levels of illumination were determined in separate experiments [18] by measuring the rate of photolysis of NO2 in N2 using the quartz-tube, continuous flow technique of Zafonte et al [19].…”

Section: Methodsmentioning

confidence: 99%

Experimental investigation of chamber‐dependent radical sources

Carter

Atkinson

Winer

et al. 1982

Int J of Chemical Kinetics

124

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While environmental chamber data have been widely used to generate and validate computer models of the chemistry occurring in polluted atmospheres, the effects of the chambers on the gas-phase chemistry being studied have been poorly characterized. In order to investigate such chamber effects, a series of NO,-air irradiations, with trace levels of organics present to monitor OH radical concentrations, have been carried out in four different environmental chambers (ranging in volume from -100 to 40,000 L) at varyiing temperatures, humidities, pressures, and reaction conditions. In addition, a number of control experiments have been carried out to validate the technique for measuring OH radical levels in these irradiations. The data show that unknown sources of OH radicals are present in all of the chambers studied. The data are consistent with the presence of two distinct radical sources: (1) the photolysis of initially present HONO, whose importance increases with increasing N O D O concentration ratios, but which is a minor contributor to the overall radical flux after 30-60 min of irradiation, and (2) a constant (for these NO,-air irradiations) radical source which dominates beyond approximately the first 60 min of irradiation. The radical input rates, after the first -30-60 min of irradiation, are independent of the h10 concentration, increase with increasing temperature, humidity, and NO2 concentration, are proportional to light intensity, and are dependent on the chamber employed. Although the exact nature of this radical source is still undetermined, results of experiments reported here allow a number of possible mechanisms to be ruled out, and these are discussed.

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Section: Methodsmentioning

confidence: 99%

Experimental investigation of chamber‐dependent radical sources

Carter

Atkinson

Winer

et al. 1982

Int J of Chemical Kinetics

124

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“…

{[{NO}_{2}]}_{degradation} = k_{2} ([], {NO}_{2})

where k 2 is the reaction rate of equation . The value of k 1 and k 2 are 3.3 × 10 3 exp(−1430/ T ) (ppm −1 min −1 ) [ Baulch et al , ] and 0.45 min −1 [ Darnall et al ., ], respectively. Thus, the values calculated from equations and are the formation and decomposition of NO 2 per minute.…”

Section: Resultsmentioning

confidence: 99%

The impact of air pollutants on rainwater chemistry during “urban‐induced heavy rainfall” in downtown Tokyo, Japan

et al. 2017

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In order to clarify the impact of air pollution on the formation of sudden and locally distributed heavy rain in urban areas (hereafter UHR = urban‐induced heavy rain), we analyzed inorganic ions in rainwater samples collected on an event basis over 5 years from October 2012 to December 2016 in Shinjuku, Tokyo. Hourly rainfall amounts and wet deposition fluxes of acidic components (the sum of H+, NH4+, NO3−, and nonsea‐salt SO42−) in UHR were 13.1 and 17.8 times larger than those in normal rainfall, respectively, indicating that large amount of air pollutants were scavenged and deposited by UHR with large amounts of rainfall. The level of air pollutants, such as NO2, SO2, and potential ozone, in the ambient air increased just before the formation of UHR and decreased sharply at the end of the UHR event. These results indicate that NO2, which was formed secondarily by oxidants, was further oxidized by HO radicals and formed HNO3 just before the formation of UHR, which was subsequently scavenged by UHR.

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“…The irradiation intensity is usually characterized by the NO 2 photolysis rate ( J NO2 ), which has been reported to be from 0.1 min –1 to higher than 1 min –1 in different smog chambers (Table S1). Constant and diurnally varying light conditions also have an impact on O 3 formation [ 35 ]. Therefore, light conditions should be carefully characterized and taken into account to constrain the photoreactions.…”

Section: Smog Chamber: Atmospheric Process Simulatormentioning

confidence: 99%

Application of smog chambers in atmospheric process studies

Chu

Chen

et al. 2021

National Science Review

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The smog chamber experimental systems, which have been widely used in laboratory simulation for studying atmospheric processes, are comprehensively reviewed in this paper. The components, development history, main research topics, and main achievements of smog chambers are introduced. The typical smog chambers in the world, including their volumes, wall materials, light sources, and features, are summarized and compared. The key factors of smog chambers and their influences on the simulation of the atmospheric environment are discussed, including wall loss, wall emission, and background pollutants. The features of next-generation smog chambers and their application prospect in future studies of the atmospheric environment are also outlined in this paper.

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Effects of ConstantversusDiurnally-Varying Light Intensity on Ozone Formation

Cited by 6 publications

References 3 publications

Experimental investigation of chamber‐dependent radical sources

Experimental investigation of chamber‐dependent radical sources

The impact of air pollutants on rainwater chemistry during “urban‐induced heavy rainfall” in downtown Tokyo, Japan

Application of smog chambers in atmospheric process studies

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