Journal ArticleDOI
The free radical chemistry of cloud droplets and its impact upon the composition of rain
TLDR
In this article, the authors simulate the free radical chemistries of the gas phase and aqueous phase within a warm cloud during midday solar fluxes and demonstrate that the scavenging of OH and HO2 from cloud droplets can represent a major source of free radicals to cloud water provided the accommodation or sticking coefficient for these species impinging upon water droplets is not less than 0.0001.Abstract:
Calculations are presented that simulate the free radical chemistries of the gas phase and aqueous phase within a warm cloud during midday. It is demonstrated that in the presence of midday solar fluxes, the heterogeneous scavenging of OH and HO2 from the gas phase by cloud droplets can represent a major source of free radicals to cloud water, provided the accommodation or sticking coefficient for these species impinging upon water droplets is not less than 0.0001. The aqueous-phase of HO2 radicals are found to be converted to H2O2 by aqueous-phase chemical reactions at a rate that suggests that this mechanism could produce a significant fraction of the H2O2 found in cloud droplets. The rapid oxidation of sulfur species dissolved in cloudwater by this free-radical-produced H2O2 as well as by aqueous-phase OH radicals could conceivably have a significant impact upon the chemical composition of rain.read more
Citations
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Journal ArticleDOI
The cloudwater chemistry of iron and copper at great dun fell, u.k.
David L. Sedlak,Jürg Hoigné,Margaret M. David,Roy N. Colvile,Elke Seyffer,Karin Acker,Wolfgang Wiepercht,John A. Lind,Sandro Fuzzi +8 more
TL;DR: The role of iron and copper in the transformation of photooxidants (HO2/O2−) and pollutants in clouds was examined at a rural site (Great Dun Fell, U.K.).
Journal ArticleDOI
A theoretical investigation of sulfate formation in clouds
TL;DR: In this paper, the relative importance of chemical pathways that govern the atmospheric oxidation of SO2 to sulfate is investigated by means of a mathematical model of cloud chemistry and transport, and the results show that gas-phase SO2 oxidation is initially the primary pathway for sulfate formation, but subsequently the high pH values, caused by the wet removal of pollutants, favor the aqueous oxidation of O3.
Journal ArticleDOI
Impact, Trapping, and Accommodation of Hydroxyl Radical and Ozone at Aqueous Salt Aerosol Surfaces. A Molecular Dynamics Study
TL;DR: In this paper, the authors investigated collisions of the gaseous hydroxyl (OH) radical and ozone (O3) with the surfaces of sodium chloride or iodide solutions, as well as with the surface of neat water, by molecular dynamics simulations.
Journal ArticleDOI
Importance of formaldehyde in cloud chemistry
TL;DR: In this article, a physicalchemical model which is an extension of that of Hong and Carmichael (1983) is used to investigate the role of formaldehyde in cloud chemistry and assess the importance of S(IV)-HCHO adduct formation, the reduction of H2O2 by HCHO, HCHO-free radical interactions, and the formation of HCOOH in the presence of HCHO in cloud droplets.
Journal ArticleDOI
Laser-Based Studies of Reactions of the Nitrate Radical in Aqueous Solution
TL;DR: In this paper, a new experimental technique for temperature dependent studies of the kinetics of the nitrate radical (NO3) in aqueous solution has been developed, where NO3 is produced by excimer laser photolysis of peroxodisulfate anions at 351 nm in the presence of excess nitrate and detected by time-resolved long-path laser absorption using the 632.8 nm line of a HeNe-laser.
References
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Book
Microphysics of Clouds and Precipitation
TL;DR: In this article, the authors focus on one major aspect of cloud microphysics, which involves the processes that lead to the formation of individual cloud and precipitation particles, and provide an account of the major characteristics of atmospheric aerosol particles.
Journal ArticleDOI
Rate Constants for Reactions of Inorganic Radicals in Aqueous Solution
TL;DR: In this article, rate constants have been compiled for reactions of various inorganic radicals produced by radiolysis or photolysis, as well as by other chemical means in aqueous solutions.
Book
The physics of clouds
F. H. Ludlam,Basil John Mason +1 more
TL;DR: In the last fifteen years there has been a surge of activity in this science under the stimulus of development in civil and military aviation as discussed by the authors, and the growth of cloud physics during this period has been fostered not only by this general invigoration, but also by recognition of the practicability of exerting some influence upon the behaviour of clouds and their capacity for producing rain, hail, lightning and other meteorological phenomena.
Journal ArticleDOI
Normal atmosphere: large radical and formaldehyde concentrations predicted.
TL;DR: A radical chain reaction is proposed for the rapid removal of carbon monoxide, leading to acarbon monoxide lifetime as low as 0.2 year in the surface atmosphere.
Book
Highly dispersed aerosols
N.A. Fuchs,A.G. Sutugin +1 more
TL;DR: In this article, the processes leading to the formation of high-dispersed aerosols with particle size below 0.1 μ and the methods of generation and investigation of these aerosols are treated as well as their physical properties differing fundamentally from those of coarse aerosols.