Accession Number : AD0725366

Title :   Evolution of the Fog Droplet Size Distribution Observed by Laser Scattering,

Corporate Author : ISTITUTO DI FISICA DELL'ATMOSFERA ROME (ITALY)

Personal Author(s) : Ferrara,R. ; Fiocco,G. ; Tonna,G.

Report Date : 17 MAR 1970

Pagination or Media Count : 9

Abstract : Scattering of a continuous wave He-Ne laser beam in artificial fog is observed by five photometers at different angles. The measured intensity of the light scattered in the different directions is related to a T-type spectral distribution of the droplet sizes during the various evolution stages of the fog. The artificial fog is produced in a 40 cubic meter chamber, where the main physical parameters (vapor and nuclei concentration, temperature) can be controlled to reproduce the complete evolution process. The fog droplet size spectrum is determined at intervals of about 1 min. The results show that the size distribution shifts towards larger size droplets during condensation, and that the shift is reversed during fog dissipation. (Author)

Descriptors :   (*FOG, LIGHT TRANSMISSION), (*COHERENT RADIATION, SCATTERING), AEROSOLS, EXPERIMENTAL DESIGN, OPTICAL PROPERTIES, ITALY

Subject Categories : Atmospheric Physics
      Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE