Infrared properties of haze particles of Venus

The computed variation of the infrared flux and polarization of Venus as a function of phase angle, based upon multiple-scattering calculations for the cloud model of Kawabata et al. (1980) with an internal heat source, precludes the possibility of sulfuric acid as the composition of the haze particles located above the main cloud. Furthermore, our calculations reveal that the hazticle should have a large absorption coefficient at these wavelengths, i.e, $\text{k(}\text{imaginary part of the complex refractive index}\text{) ? 1.3}\text{at a wavelength}\text{λ = 3.4 μ}\text{m}$. The optical thickness of the haze layer must be about 0.15 at λ = 3.4 μm.