Accession Number : ADA330527

Title :   The Asymmetry Parameter and Aggregate Particles

Descriptive Note : Progress rept. 1 Oct 96-1 Apr 97

Corporate Author : ARMY RESEARCH LAB ADELPHI MD

Personal Author(s) : Videen, Gorden ; Pinnick, Ronald G. ; Ngo, Dat ; Fu, Qiang ; Chylek, Petr

PDF Url : ADA330527

Report Date : OCT 1997

Pagination or Media Count : 26

Abstract : We derive and examine the general expression for the scattering asymmetry parameter g. For aggregate particles, the asymmetry parameter is made up of two terms. One term accounts for interference effects of the electromagnetic fields radiating from the individual subsystems. The other term accounts for interaction effects of the electromagnetic fields between these subsystems. Enhanced backscatter is one phenomenon resulting from these interactions. Numerical results demonstrate that interference effects play a dominant role when the separation distance between aggregates is smaller than half the incident wavelength. As the separation distance becomes large, both interference and interaction effects drop off, and the asymmetry parameter approaches that of the individual particle constituents.

Descriptors :   *RADIATIVE TRANSFER, *CIRRUS CLOUDS, ELECTROMAGNETIC FIELDS, LIGHT SCATTERING, BACKSCATTERING, ASYMMETRY, CLOUD PHYSICS.

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE