Sizes of cloud droplets and cloud droplet residues near stratus cloud base

A Model for Particle Microphysics, Turbulent Mixing, and Radiative Transfer in the Stratocumulus-Topped Marine Boundary Layer and Comparisons with Measurements

“…The prediction by our model of large, unactivated haze particles above cloud base is supported by the measurements of Akagawa and Okada ( 1993 ), who tound high concentrations of small droplets (r < 2.5 _m) near the base of stratus clouds. However, the height dependence of droplet concentration and its sensitivity to the particle size cutoff may also be artifacts of our 1D model.…”

Aircraft measurements of single particle size and composition reveal aerosol size and mixing state dictate their activation into cloud droplets

“…Therefore, the reported composition and size of droplet residuals are expected to be representative of the entire droplet population, since larger droplets are not necessarily associated with more hygroscopic and/or larger residual particles. 57…”

“…Therefore, the reported composition and size of droplet residuals are expected to be representative of the entire droplet population, since larger droplets are not necessarily associated with more hygroscopic and/or larger residual particles. 57 Aerosol size distributions (mobility diameter, d m ) in the size range from 10 nm to 0.4 mm were measured using a fast integrated mobility spectrometer (FIMS) 58 and used to quantify total particle number concentrations and concentration of particles in accumulation mode (with diameters >0.1 mm). Cloud condensation nuclei (CCN) measurements were performed using a cloud condensation nuclei counter (CCNC, DMT), 59 operating at two instrument supersaturations: 0.24% and 0.46%.…”

On the relative density of clouds

“…We can estimate an order of magnitude of M c using a typical droplet size for Earth's clouds. Observations of the size distribution of cloud droplets near stratus cloud base show high number concentrations of small droplets <2.5 μ m radius (Akagawa and Okada, ). For a cloud with droplets with this radius, we estimate M c =4×10 10 kg mol −1 , R c ∼2×10 −10 J K −1 kg −1 and , then compared with .…”