EXPERIMENTAL-DETERMINATION OF THE CONNECTION BETWEEN CLOUD DROPLET SIZE AND ITS DRY RESIDUE SIZE

The droplet activation process and droplet growth was studied during e arly stages of the formation of orographically-induced clouds. The exp erimental results were compared with the results obtained with a close d parcel, adiabatic cloud model. Good agreement was in most cases foun d between model and measurements with respect to cloud droplet number concentration, cloud droplet solute concentration and particle sizes s cavenged due to cloud droplet nucleation. The experimental results wer e mainly obtained with a new instrument, the droplet aerosol analyser (DAA), which allows the determination of ambient sizes of cloud drople ts and interstitial aerosol particles directly connected with the size of its dry residue in a two-parameter data acquisition. The resulting three-dimensional data set (ambient size, dry size, number concentrat ion) was utilised to determine several cloud/aerosol properties, where of some unique. (C) 1996 Elsevier Science Ltd.