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Dr. William Farrell 

NASA/Goddard Space Flight Center

November 9th, 2016, 3:30PM,  
Thirkield Hall (Physics), room 103

Do Mars dust devils and storms generate electricity?  [PDF]

ABSTRACT:  Dust devils and dust storms exist both on Earth and Mars. Dust devils, in particular, are known to have distinct meteorological (fluid) signatures, including cyclonic winds and thermally-hot centers.  However, in arid environments like Earth’s desert, wind and dust also produce electricity through a process call “tribo-electricity”, where mixing dust and sand grains of different composition and size both generate and exchange electric charge upon collision. In this presentation, we will discuss the micro-physics of tribo-electricity, and describe applications of this charging process to large coherent convective structures such as dust devil and dust storms. Modeling and laboratory efforts will be described along with the instrumentation required to quantify the most fundamental electrical and fluid variables. Especially highlighted will be terrestrial desert analog field studies of dust devils that demonstrate their physical impressiveness and electrical complexity.  Extrapolating these results, it will become apparent that Mars might also possess a very complex dust-driven atmospheric electrical environment - an environment that has yet to be fully explored.