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
Sulfur dioxide oxidation in clouds at Whiteface Mountain as a function of drop size
Oliver V. Rattigan,Jill E Reilly,Christopher D. Judd,K. Moore,Mita Das,D. Eli Sherman,Vincent A. Dutkiewicz,Jeffrey L. Collett,Liaquat Husain +8 more
TL;DR: In situ oxidation of SO2 has been determined in clouds as a function of droplet size using a trace element technique during July 1998 at Whiteface Mountain, New York.
Journal ArticleDOI
A field study of the oxidation of SO2 in a cap cloud at Great Dun Fell
A. S. Chandler,Thomas Choularton,G. J. Dollard,Martin Gallagher,T. A. Hill,B. M. R. Jones,Stuart A. Penkett,B. J. Tyler,Brian J. Bandy +8 more
TL;DR: A series of field experiments has been performed in natural cloud on Great Dun Fell to investigate the multiphase oxidation of sulphur dioxide by hydrogen peroxide and ozone as discussed by the authors, and it was found that hydrogen was generally the most important oxidant for sulphate in the cloud.
Journal ArticleDOI
Contrasting behavior of gas and aerosol scavenging in convective rain: A numerical and experimental study in the African equatorial forest
Sylvie Cautenet,B. Lefeivre +1 more
TL;DR: In this paper, a two-dimensional convective cloud model was coupled with a chemical model consisting of the explicit prediction of five chemical species: SO2, SO42−, NH4+, O3, and H2O2.
Journal ArticleDOI
Sensitivity analysis of the role of free radical, organic and transition metal reactions in sulfate production in clouds
TL;DR: In this paper, the role of free radicals, organic compounds and transition metals on in-cloud sulfate production was studied using a flow through reactor model approach, and the sensitivity of the model predictions to initial conditions and model parameters were evaluated by calculation of local elementary sensitivity coefficients and by calculating of the Green's function.
Journal ArticleDOI
Observations and modeling of OH and HO2 radicals in Chengdu, China in summer 2019
Xinping Yang,Keding Lu,Xuefei Ma,Yanhui Liu,Haichao Wang,Renzhi Hu,Xin Li,Shengrong Lou,Shiyi Chen,Huabin Dong,Fengyang Wang,Yihui Wang,Guoxian Zhang,Shule Li,Suding Yang,Yiming Yang,Cailing Kuang,Zhaofeng Tan,Xiaorui Chen,Peipei Qiu,Limin Zeng,Pinhua Xie,Yuanhang Zhang +22 more
TL;DR: In this paper, the first continuous measurements of ambient OH and HO2 radicals at a suburban site in Chengdu, Southwest China, which were collected during 2019 as part of a comprehensive field campaign ‘CompreHensive field experiment to explore the photochemical Ozone formation mechaniSm in summEr - 2019 (CHOOSE-2019)’ were reported.
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.
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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.
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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.
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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.
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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.