INFLUENCES OF CLOUD PHOTOCHEMICAL PROCESSES ON TROPOSPHERIC OZONE

Global models of atmospheric chemistry typically neglect the chemical effects of clouds. Although clouds occupy only about 15% of the volume of the lower troposphere, and the volume fraction of liquid water in clouds is only 10-7 to 10-6, aqueous-phase chemistry is shown to decrease significantly ozone concentrations in the troposphere. Hydroxyl, formaldehyde and nitrogen oxide concentrations are decreased as well, thereby reducing the oxidation and cleansing efficiency of the troposphere and influencing the atmospheric budgets of many trace gases. © 1990 Nature Publishing Group.