Influence of humidity on the light-scattering characteristics of radially inhomogeneous aerosol particles in the boundary layer over an ocean

The light-scattering characteristics of the particles comprising the sulfate and sea-salt components of a marine aerosol are investigated in the approximation of models of polydisperse ensembles (of translucent, two-layer, and homogeneous spheres). It is established that at a low relative humidity the light-scattering coefficient and indicatrix of the particles (at small scattering angles) are weakly sensitive to variations of the atmospheric humidity. At values of the relative humidity greater than 60% disregard of the radial inhomogeneity of the structure of the particles can lead to large errors (greater than 50%) in estimating the scattering indicatrix and the degree of linear polarization in the range of large scattering angles that is most informative in remote methods for studying oceans. Appreciable depolarization of the scattered light is discovered for the sea-salt component. (C) 2000 The Optical Society of America.