Optical properties of water-coated sea salt model particles.

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.

Aerosol optics model for black carbon applicable to remote sensing, chemical data assimilation, and climate modelling.

Aerosol optics models are an integral part of of climate models and of retrieval methods for global remote sensing observations. Such large-scale environmental applications place tight constraints on the affordable model complexity, which are difficult to reconcile with the considerable level of detail that is needed to capture the sensitivity of optical properties to morphological aerosol characteristics. Here, we develop a novel core-grey-shell dimer model and demonstrate its potential for reproducing radiometric and polarimetric properties of black carbon aerosols.

Convergence of the iterative T-matrix method.

Among the various methods for computing the T-matrix in electromagnetic and acoustic scattering problems is an iterative approach that has been shown to be particularly suited for particles with small-scale surface roughness. This method is based on an implicit T-matrix equation. However, the convergence properties of this method are not well understood.

Multiple scattering by aerosols as seen from CALIPSO - a Monte-Carlo modelling study.

The impact of multiple scattering (MS) by aerosols on satellite-borne lidar measurements is studied by Monte-Carlo radiative transfer simulations. A total of 48 aerosol scenarios are considered. We find that the frequently used MS correction factor can be parameterized as a function of aerosol size and aerosol optical depth.

Coating material-dependent differences in modelled lidar-measurable quantities for heavily coated soot particles.

The optical properties of thickly coated soot particles are sensitive to the chemical composition, thus to the refractive index of the coating material. For 58 differently sized coated soot aggregates the extinction-to-backscatter ratio (lidar ratio) and the depolarisation ratio are computed at a wavelength of 355 nm, 532 nm and 1064 nm for two different coating materials: a toluene-based coating and a sulphate coating. Additionally the Ångström exponents between 355 nm and 532 nm as well as between 532 nm and 1064 nm are calculated.