Abstract
Dust devils are low-pressure, small (many to tens of meters) convective vortices powered by surface heating and rendered visible by lofted dust. Dust devils occur ubiquitously on Mars, where they may dominate the supply of atmospheric dust, and since dust contributes significantly to Mars’ atmospheric heat budget, dust devils probably play an important role in its climate. The dust-lifting capacity of a devil likely depends sensitively on its structure, particularly the wind and pressure profiles, but the exact dependencies are poorly constrained. Thus, the exact contribution to Mars’ atmosphere remains unresolved. Analog studies of terrestrial devils have provided some insights into dust devil dynamics and properties but have been limited to near-surface (few meters) or relatively high altitude (hundreds of meters) sampling. Automated aerial vehicles or drones, combined with miniature, digital instrumentation, promise a novel and uniquely powerful platform from which to sample dust devils at a wide variety of altitudes. In this article, we describe a pilot study using an instrumented quadcopter on an active field site in southeastern Oregon, which (to our knowledge) has not previously been surveyed for dust devils. We present preliminary results from the encounters, including stereo image analysis and encounter footage collected onboard the drone. In spite of some technical difficulties, we show that a quadcopter can successfully navigate in an active dust devil, while collecting time-series data about the dust devil’s structure.
Highlights
Powered by surface heating, dust devils are low-pressure convective vortices rendered visible by lofted dust
The limited success of our stereo-imaging hindered a robust assessment of the dust devils’ pressure profiles, the primary goal of our survey was to show that the drone could stably navigate and pass through a dust devil. With this success from the pilot study, we have shown that probing dust devils with this unique platform has tremendous potential to reveal novel insights into dust devil dynamics and processes
When we attempted to estimate the distance to dust devil 1 encountered during Flight 1, for several of the still images, we found a distance of roughly 80 m, which is consistent with the apparent encounter timing for the drone, but, for several other images, the distance estimates were inconsistent
Summary
Dust devils are low-pressure convective vortices rendered visible by lofted dust. Perhaps a more important bias for these surveys is that dust devils are unlikely to pass directly over the sensor package, i.e., the miss distance is non-zero, which means that the pressure, temperature, and wind profiles recovered do not directly reflect the values at the dust devil center Instead, they represent a convolution between the intrinsic properties of the devil and the encounter geometry. Other studies have actively chased dust devils in order to probe their structures using instruments mounted on vehicles [18,19], allowing a more controlled encounter geometry, but both kinds of studies, active and passive, have usually been limited to measuring near-surface properties of dust devils ( seminal work in [20] used a sailplane to sample dust devil thermals at altitudes above 2000 ft.) To address these shortcomings, we conducted a pilot study using an instrumented quadcopter or drone on the Alvord Desert playa in southeastern Oregon, a site that, to our knowledge, has never before been surveyed for dust devils. With this success from the pilot study, we have shown that probing dust devils with this unique platform has tremendous potential to reveal novel insights into dust devil dynamics and processes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
