Analysis and Optical Modeling of Individual Heterogeneous Asian Dust Particles Collected at Mauna Loa Observatory

This project involved the analysis and optical modeling of atmospheric dust particles collected at Mauna Loa Observatory in Hawaii. Dust from the Asian mainland was identified in filter samples with computer-controlled scanning electron microscopy (CC-SEM). Individual Asian dust and marine background air particles were further examined using focused ion-beam (FIB) SEM and energy dispersive x-ray spectroscopy (EDX). The particles were heterogeneous in that they had multiple mineral phases, including an iron-containing phase which was compositionally minor but optically important. FIB tomography was used to produce 3-D reconstructions of the particles. The discrete dipole approximation (DDA) method for calculating optical properties was used to determine the light-scattering behavior of the particles based on the 3-D reconstructions. The dataset includes the following:
1) Tabulated optical property results for all selected particles in a single Excel file
2) Folder with CC-SEM data files
3) Folder and subfolders with particle SEM images and EDX element maps
4) Folder with Excel files with element composition, oxide composition, mineral composition, and mineral phase volumes for each particle
5) Folder and subfolders with optical modeling parameter files
6) Folder and subfolders with input and output files from the DDA program DDSCAT ver. 7.3.
7) Folder with Excel files with backscatter fraction calculations