title: Variability in nocturnal nitrogen oxide processing and its role in regional air quality.
abstract: Nitrogen oxides in the lower troposphere catalyze the photochemical production of ozone (O3) pollution during the day but react to form nitric acid, oxidize hydrocarbons, and remove O3 at night. A key nocturnal reaction is the heterogeneous hydrolysis of dinitrogen pentoxide, N2O5. We report aircraft measurements of NO3 and N2O5, which show that the N2O5 uptake coefficient, g(N2O5), on aerosol particles is highly variable and depends strongly on aerosol composition, particularly sulfate content. The results have implications for the quantification of regional-scale O3 production and suggest a stronger interaction between anthropogenic sulfur and nitrogen oxide emissions than previously recognized.
authors.affiliation: National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory, R/CSD2, 325 Broadway, Boulder, CO 80305, USA. steven.s.brown@noaa.gov
authors.forename: S S
authors.initials: SS
authors.lastname: Brown
authors.forename: T B
authors.initials: TB
authors.lastname: Ryerson
authors.forename: A G
authors.initials: AG
authors.lastname: Wollny
authors.forename: C A
authors.initials: CA
authors.lastname: Brock
authors.forename: R
authors.initials: R
authors.lastname: Peltier
authors.forename: A P
authors.initials: AP
authors.lastname: Sullivan
authors.forename: R J
authors.initials: RJ
authors.lastname: Weber
authors.forename: W P
authors.initials: WP
authors.lastname: Dubé
authors.forename: M
authors.initials: M
authors.lastname: Trainer
authors.forename: J F
authors.initials: JF
authors.lastname: Meagher
authors.forename: F C
authors.initials: FC
authors.lastname: Fehsenfeld
authors.forename: A R
authors.initials: AR
authors.lastname: Ravishankara