Chemical conversions in clouds

Conference · Mon Jul 01 00:00:00 EDT 1985

OSTI ID:5257497

Schwartz, S E

Clouds constitute an extreme atmospheric aerosol in terms of particle size and condensed-phase mass. The large amount of liquid water in clouds as well as the high state of dispersion make clouds a potentially important medium for atmospheric reactions, depending upon thermochemical driving force and chemical kinetics of particular reactions. This paper presents the formalism for evaluating the rates of in-cloud reactions making use of laboratory-determined physical-chemical properties and assumed or measured reagent concentrations and other situational variables. Accurate description of these rates is sensitive to the mass-accommodation coefficient ..cap alpha.. (fraction of gas kinetic collisions at the air-water interface effective in transfering gaseous species to cloud droplets) if ..cap alpha..< 0.01. Little information pertinent to ..cap alpha.. is available for relevant solute gases. Attention is directed to reaction of SO/sub 2/ and NO/sub 2/ to form sulfuric and nitric acids, respectively, and to reactions involving oxidants (O/sub 3/, H/sub 2/O/sub 2/) and free radicals (HO, HO/sub 2/). Important in-cloud reactions identified include aqueous-phase oxidation of SO/sub 2/ by H/sub 2/O/sub 2/ and O/sub 3/ and gas-phase oxidation of NO/sub 2/ by O/sub 3/ followed by uptake of N/sub 2/O/sub 5/ or NO/sub 3/ by cloudwater. 141 refs., 8 figs., 5 tabs.

• Research Organization: Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5257497
• Report Number(s): BNL-36923; CONF-8505106-1; ON: DE86000033
• Resource Relation: Conference: 2. US-Dutch international symposium on aerosols, Williamsburg, VA, USA, 19 May 1985
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CLOUDS
ATMOSPHERIC CHEMISTRY
NITROGEN DIOXIDE
OXIDATION
SULFUR DIOXIDE
CHEMICAL REACTIONS
REACTION KINETICS
CHALCOGENIDES
CHEMISTRY
KINETICS
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
SULFUR COMPOUNDS
SULFUR OXIDES
500200* - Environment
Atmospheric- Chemicals Monitoring &amp; Transport- (-1989)