Optical properties of water-coated sea salt model particles

Abstract

We investigate the optical properties of marine aerosol in dependence of the water content. To this end we develop a model geometry that realistically mimics the morphological changes as the salt particles take up more water. The results are compared to morphologically simpler models, namely, homogeneous and inhomogeneous superellipsoids, as well as cube-sphere hybrids. The reference model yields depolarization ratios, depending on size and water uptake, in the range from 0 to 0.36 ± 0.12. Overall, the simple models can reproduce optical properties of the reference model. The overall nonsphericity, as well as inhomogeneity are identified as key morphological parameter, while rounding of edges only has a minor impact on optical properties.