The role of transition metal ions on HOx radicals in clouds: a numerical evaluation of its impact on multiphase chemistry

[摘要] A new modelling study of the role of transition metal ions on cloudchemistry has been performed. Developments of the Model of Multiphase CloudChemistry (M2C2; Leriche et al., 2001) are described, including the transition metal ions reactivity emission/deposition processes and variablephotolysis in the aqueous phase. The model is then applied to three summertime scenarios under urban, remote and marine conditions, described byErvens et al. (2003).

Chemical regimes in clouds are analyzed to understand the role of transitionmetal ions on cloud chemistry and especially, on H_xO_y chemistry,which consequently influences the sulphur and the VOCs chemistry in droplets. The ratio of Fe(II)/Fe(III) exhibits a diurnal variation withvalues in agreement with the available measurements of Fe speciation. In theurban case, sensitivity tests with and without TMI chemistry, show an enhancement of OH concentration in the aqueous phase when TMI chemistry isconsidered.

[学科分类] 大气科学