Retrieving Dust Properties by Radiative Transfer Modelling of Dust Devils on Earth and Mars

To date, characterisation of dust devils by interpreting spectral measurements taken during a transit over a spectroscopic instrument has yet to be done and would provide valuable information of the physical size, dust load and internal structure of transiting dust devils. A Monte Carlo Radiative Transfer model (MCRT) was developed to investigate the spectral variations during a dust devil transit. Our results show that amount of scattered and the total flux are dependent on different components of the dust devil. The scattered component is highly dependent on the optical depth per unit length (τL) making it sensitive to the internal dust distribution and physical structure. This dependence is not observed for total flux which is strongly dependent on the total amount of dust present along the path joining the light source to the detector.