<title>Definition of particle size of the Mars aerosol layer using the radiometer Termoscan panoramas obtained during the Phobos-2 flight</title>

Abstract

Some of the double channel scanning radiometer Termoscan panoramas were interpreted as those arising in the presence of the aerosol layer containing ice particles in the Mars atmosphere. The radiation fluxes registered by the radiometer where the effect of the Mars surface is omitted shows that the ratio of radiation fluxes at scattering angle (Theta) equals 177 degrees and (Theta) equals 179.5 degrees for different regions in the Mars atmosphere is rather stable and is of the order of 1.08 - 1.14. The models of aerosol medium microstructure in the form of a polydisperse distribution of spherical particles as well as the form of systems of nonspherical particles of cubic and hexagonal forms of equal size (the hexagonal prism length is equal to its diameter) with a chaotic orientation in space have been used. The range of the theoretical ratio of radiation fluxes for spherical particles (0.7 < r32 < 0.9 micrometer), where r32 is the ratio of the third moment of the particle size distribution to its second moment, corresponds to the fluxes ratio range above-mentioned. For nonspherical particles equal in size with the same values of r32 as for spherical particles the values of r32 appear somewhat smaller (approximately 15%) than for spheres.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.