The Electric Environment of Martian Dust Devils
Abstract
While Martian dust devils have been monitored through decades of observations, we have yet to study their possible electrical effects from in situ instrumentation. However, evidence for the existence of active electrodynamic processes on Mars is provided by laboratory studies of analog material and field campaigns of dust devils on Earth. We have enabled our Mars regional scale atmospheric model (MRAMS) to estimate an upper limit on electric fields generated through dust devil circulations by including charged particles as defined from the Macroscopic Triboelectric Simulation (MTS) code. MRAMS is used to investigate the complex physics of regional, mesoscale, and microscale atmospheric phenomena on Mars; it is a 3-D, nonhydrostatic model, which permits the simulation of atmospheric flows with large vertical accelerations, such as dust devils. MTS is a 3-D particle code which quantifies charging associated with swirling, mixing dust grains; grains of pre-defined sizes and compositions are placed in a simulation box and allowed to move under the influence of winds and gravity. Our MRAMS grid cell size makes our results most applicable to dust devils of a few hundred meters in diameter. We have run a number of simulations to understand the sensitivity of the electric field strength to the particle size and abundance and the amount of charge on each dust grain. We find that Efields can indeed develop in Martian dust convective features via dust grain filtration effects. The overall value of these E-fields is strongly dependent upon dust grain size, dust load, and lifting efficiency, and field strengths can range from 100s of mV/m to 10s of kV/m.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.P33I..04B
- Keywords:
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- 3346 Planetary meteorology;
- ATMOSPHERIC PROCESSES;
- 6225 Mars;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS;
- 5405 Atmospheres;
- PLANETARY SCIENCES: SOLID SURFACE PLANETS;
- 5445 Meteorology;
- PLANETARY SCIENCES: SOLID SURFACE PLANETS