Insolation of the Martian soil leads to a sub-surface overpressure due to thermal creep gas flow. This could support particle entrainment into the atmosphere. Short time shadowing e.g. by the traverse of a larger dust devil would enhance this effect. We find in microgravity experiments that mass ejection rates are increased by a factor of 10 for several seconds if a light source of 12.6 kW/m2 is turned off. Scaled to Mars this implies that self-shadowing of a partially opaque dust devil might lead to a strongly amplified flux of lifted material. We therefore suggest that self-shadowing might be a mechanism on Mars to increase the total dust loading of a dust devil and keep it self-sustained.
Cite
@article{arxiv.1603.08141,
title = {Amplification of dust loading in Martian dust devils by self-shadowing},
author = {Markus Kuepper and Gerhard Wurm},
journal= {arXiv preprint arXiv:1603.08141},
year = {2016}
}