Estimated relative abundance of chlorine nitrate among stratospheric chlorine compounds

Abstract

The temperature dependence is approximately T~3, leading to a rate constant for formation about a factor of 2 to 3 higher at stratospheric temperatures. (23) Reference 16 also reports a rapid reaction of CI0N02 with S02 and N02, but we have not observed such reactions at room temperature. (24) D. Wuebbles and F. Luther, unpublished calculations. (25) P. Crutzen, Joint IAOC/ICACGP Symposium on Atmospheric Ozone,

Atmospheric chemistry: response to human influence

“…Figure 16 shows a comparison of computed concentrations for acidic chlorine, taken as HCl + ClN0 3 + HOCl, with measurements by Lazrus et al (1976). (Rowland et al 1976a). Major uncertainties remain however and clearly point to the need for a careful observational search for CIN0 3 • Results presented here are in accord with a recent observational upper limit to the concentration of CIN0 3 set by Murcray et al (1977).…”

“…A new development in stratospheric chemistry concerns the potential importance of ClN0 3 (Rowland, Spencer & Molina 1976a). Chlorine nitrate is formed by CIO + N0 2 + M-+ ClN0 3 + M, …”

Ab initio Studies of ClOx Reactions: Prediction of the Rate Constants of ClO+NO2 for the Forward and Reverse Processes

“…As seen in Figure 2 formation of pt-ClOONO needs to overcome a high barrier (22.8 kcal mol À1 ) and the isomerization from ClONO 2 to pc-ClOONO also has a high barrier (31.8 kcal mol À1 ), therefore, the rate constants for the formation of ptClOONO and pc-ClOONO from ClO + NO 2 are negligible and are not included in this calculation. The pressure-and temperature-dependent rate constants for the association reaction were calculated with the Variflex code shown in Equation (3): [37] ClO þ NO 2 …”

“…Their association product ClONO 2 , via the reaction given in Equation (1), has been considered as one of the most important temporary reservoir species of reactive chlorine radicals. [1][2] ClO þ NO 2 …”

“…Zahniser et al [5] reported the rates in N 2 and He at 297 K and 251-365 K, respectively. In 1982, Lee et al [6] investigated this reaction in He, N 2 and O 2 at 250-387 K, 297 K and 250-416 K, respectively. The deviation of these measurements at room temperature is around AE 15 % with He as a third body; in N 2 , the largest discrepancy is around 38 %.…”