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Heterogeneous Reactions of Chlorine Nitrate and Dinitrogen Pentoxide on Sulfuric Acid Surfaces Representative of Global Stratospheric Aerosol Particles
Author(s) -
Manion Jeffrey A.,
Fittschen Christa M.,
Golden David M.,
Williams Leah R.,
Tolbert Margaret A.
Publication year - 1994
Publication title -
israel journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.908
H-Index - 54
eISSN - 1869-5868
pISSN - 0021-2148
DOI - 10.1002/ijch.199400039
Subject(s) - sulfuric acid , chemistry , aerosol , chlorine , inorganic chemistry , sulfate , nitrate , stratosphere , ozone , analytical chemistry (journal) , environmental chemistry , meteorology , organic chemistry , physics
Increasing evidence from field measurements, modeling studies, and laboratory experiments suggests that heterogeneous reactions on stratospheric sulfate aerosol particles can change the partitioning in the nitrogen and chlorine families and thereby affect global ozone levels. In this study, a Knudsen cell flow reactor was used to measure the uptake of ClONO 2 and N 2 O 5 by sulfuric acid solutions representative of background and volcanic stratospheric aerosol particles. The uptake coefficient (γ) of chlorine nitrate on 50–75 wt% H 2 SO 4 at 223 K was found to be markedly dependent on the acid concentration, with γ ranging from about 1 × 10 −2 to 1 × 10 −4 . These results are in good agreement with literature reports and the data fit the expression log γ= 1.87 – 0.074 × (wt% H 2 SO 4 ). This reaction will thus have its largest impact when stratospheric temperatures are low and sulfuric acid aerosols are most dilute. Uptake of N 2 O 5 was studied on solutions with compositions in the range 58–96 wt% H 2 SO 4 at temperatures from 193 to 303 K. N 2 O 5 reacted readily on sulfuric acid surfaces with uptake coefficients of about 0.06. The uptake coefficient was found to be independent of the sulfuric acid concentration and the solution temperature over the ranges studied. These results suggest that the reaction of N 2 O 5 with H 2 O will occur readily on sulfuric acid aerosol particles for most stratospheric conditions.