Abstract
A modelling study of the effects of aqueous phase cloud chemistry in changing the activated cloud condensation nucleus (CCN) spectrum is presented. The chemistry model is contained within a model of the development of a hill cap cloud. The aqueous phase oxidation of sulphur (IV) to sulphur (VI) by the oxidants ozone and hydrogen peroxide is considered for each of the explicit cloud-droplet categories. All gases enter cloud droplets at a finite rate which is calculated in the model. With updraughts typical of a stratocumulus-type cloud, droplet effective radii are seen to be lowered by up to 3 μm, 500 m above cloud base. However, the reduction in effective radius is expected to be important only on local scales close to the sources of new aerosol, where the processing of the CCN spectrum by clouds may be occurring for the first time. Additional cloud processing will lead to changes in the direct radiative properties of the aerosols but will have little effect upon the radiative properties of clouds subsequently forming on them. -from Authors
| Original language | English |
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| Pages (from-to) | 655-679 |
| Number of pages | 24 |
| Journal | Quarterly Journal of the Royal Meteorological Society |
| Volume | 119 |
| Issue number | 512 |
| Publication status | Published - 1993 |