Optical Modeling of Single Asian Dust and Marine Air Particles: A Comparison with Geometric Particle Shapes for Remote Sensing

The project that produced these data involved the analysis and modeling of atmospheric Asian dust particles and background marine air particles collected in Hawaii, USA at the Mauna Loa Observatory (MLO) of the National Oceanic and Atmospheric Administration. Individual heterogeneous dust particles were analyzed with focused ion-beam scanning electron microscopy and energy-dispersive X-ray spectroscopy. Three-dimensional spatial and composition models of the particles from focused ion-beam tomography were used in the calculation of optical properties by the discrete dipole approximation method with incident light at 589 nm. Optical properties included the phase function, extent of linear polarization, scattering, backscattering, and extinction cross sections, and the backscatter fraction. In addition, the project involved optical property calculations for particles as geometric shapes with volumes equivalent to those of the MLO particles. Shapes modeled for each particle included spheres, spheroids, ellipsoids, cubes, square prisms, rectangular prisms, tetrahedra, and triangular pyramids. The representation of particles as geometric shapes is an important component of algorithms used in remote sensing (satellite-based and ground-based) for determining how atmospheric dust affects climate.