The Diurnal Variation of the Neutral Sodium Species in the Upper Atmosphere. A Model Study.

Rodríguez, José M.; Ko, Malcolm K. W.; Sze, Nien Dak

doi:10.21236/ada154988

Cited by 2 publications

(1 citation statement)

References 32 publications

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“…[18][19][20][21] Such a lifetime is in the range where modeling of global surface deposition must take into account the regional distribution of rain-out removal rates. It should be noted that equations 3 and 4 and Figure 2 are strictly applicable only for x > 5 days.…”

Section: Atmospheric Fate Of Halocarbonyl Oxidation Intermediatesmentioning

confidence: 99%

Heterogeneous Atmospheric Chemistry of Alternative Halocarbon Oxidation Intermediates

Kolb

Worsnop

Zahniser

et al. 1997

ACS Symposium Series

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Alternative halocarbons designed to substitute for chlorofluorocarbons and halons banned by the Montreal Protocol are designed to undergo oxidative degradation in the troposphere.Intermediate partially oxygenated products from currently used alternatives include carbonyl halides, haloacetyl halides and haloacetic acids. These intermediates are expected to undergo heterogeneous reactions with aqueous cloud droplets and surface waters. The chemical and physical parameters which govern the heterogeneous uptake of a range of these species by liquid water have been measured in our laboratories using droplet train/flow tube and/or bubble column techniques. The results of these experiments will be presented and compared with available results from other laboratories. Their impact on our ability to predict the atmospheric fate of halocarbon oxidation intermediates will be discussed. Atmospheric Fate of Alternative Halocarbon Oxidation ProductsAlternative halocarbons planned as substitutes for chlorofluorocarbons and halons banned by the Montreal Protocol are designed to undergo oxidative degradation in the troposphere. Intermediate partially oxygenated products from currently used or proposed alternatives include carbonyl halides, haloacetyl halides and haloacetic acids. A wide variety of atmospheric processes could participate in the removal of relatively stable degradation intermediates, including: transport to the stratosphere followed by photolysis, uptake by both tropospheric and stratospheric aerosols, uptake by cloud droplets, rainout (wet deposition), and dry deposition to vegetation, soil and dew surfaces, and to the oceans. However, recent model analyses indicate that cloud droplet and ocean uptake are the most likely removal rate determining processes. The physicochemical processes which are important in determining the rate of trace atmospheric gas uptake by liquid surfaces include gas phase diffusion, mass accommodation, solvation (Henry's law solubility), liquid phase diffusion and liquid phase reaction. The most effective removal paths and their associated physicochemical parameters are displayed in Table I. Key parameters affecting atmospheric removal rates are the mass accommodation coefficient, a, the Henry's law constant, H, and the first order hydrolysis reaction rate coefficient, k hyd .

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Section: Atmospheric Fate Of Halocarbonyl Oxidation Intermediatesmentioning

confidence: 99%

Heterogeneous Atmospheric Chemistry of Alternative Halocarbon Oxidation Intermediates

Kolb

Worsnop

Zahniser

et al. 1997

ACS Symposium Series

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Possible impact of sodium species on ClO and O₃ in the upper stratosphere

Rodríguez¹,

Ko²,

Sze³

1986

Geophysical Research Letters

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Recent measurements of the rates for tion (4) was first recognized by Murad et al.reactions of NaO2 and NaOH with HC1 and of the (1981) who suggested that the species MC1 could photoabsorption cross section of NaC1 allow for act as an important reservoir of chlorine if its realistic estimates of the impact of sodium chem-stratospheric abundance is comparable to that of istry on chlorine partitioning in the upper strat-HC1. On the other hand, reactions (4) and (5) osphere. When sodium chemistry is incorporated into our one-dimensional model of the upper atmosphere, the results indicate that the calculated C10 concentrations near 50 km could increase by up to a factor of two with a corresponding decrease in calculated O3 abundances of as much as 15 percent.The impact on C10 and O3 depends crucially on the assumed meteoritic source of sodium, on transport from the mesosphere, and on transformation and removal of gaseous sodium in the stratosphere.Since the fluctuations in the abundance of gaseous sodium could induce O3 variations comparable to those caused by changes in temperature and solar UV, consideration of the chemistry of sodium and other metals may be an important element in efforts toward early detection of trends in upper stratospheric 03 . Future increases in stratospheric chlorine will magnify the impact of sodium species on ozone.

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The Diurnal Variation of the Neutral Sodium Species in the Upper Atmosphere. A Model Study.

Abstract: This technical report has been reviewed and is approved for publication.

Cited by 2 publications

References 32 publications

Heterogeneous Atmospheric Chemistry of Alternative Halocarbon Oxidation Intermediates

Heterogeneous Atmospheric Chemistry of Alternative Halocarbon Oxidation Intermediates

Possible impact of sodium species on ClO and O₃ in the upper stratosphere

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The Diurnal Variation of the Neutral Sodium Species in the Upper Atmosphere. A Model Study.

Abstract: This technical report has been reviewed and is approved for publication.

Cited by 2 publications

References 32 publications

Heterogeneous Atmospheric Chemistry of Alternative Halocarbon Oxidation Intermediates

Heterogeneous Atmospheric Chemistry of Alternative Halocarbon Oxidation Intermediates

Possible impact of sodium species on ClO and O3 in the upper stratosphere

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Possible impact of sodium species on ClO and O₃ in the upper stratosphere