Jean-Jacques Berthelier, Nilton O. Renno, William M. Farrell, M. Zimmerman, Erika Barth, Francesca Esposito, Cauê S. Borlina, Franck Montmessin, Grégoire Déprez, Jonathan Merrison, Keri Nicoll, R. G. Harrison, Isobel M P Houghton, Karen Aplin, Sachchida Nand Tripathi, Department of Meteorology [Reading], University of Reading ( UOR ), Southwest Research Institute [Boulder] ( SwRI ), INAF - Osservatorio Astronomico di Capodimonte ( OAC ), Istituto Nazionale di Astrofisica ( INAF ), Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] ( AOPP ), University of Oxford [Oxford], Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] ( AOSS ), University of Michigan [Ann Arbor], NASA Goddard Institute for Space Studies ( GISS ), NASA Goddard Space Flight Center ( GSFC ), Norwegian University of Science and Technology [Trondheim] ( NTNU ), Johns Hopkins University ( JHU ), UK’s Natural Environment Research Council (NE/L011514/1), University of Reading (UOR), Southwest Research Institute [Boulder] (SwRI), INAF - Osservatorio Astronomico di Capodimonte (OAC), Istituto Nazionale di Astrofisica (INAF), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan System-University of Michigan System, NASA Goddard Institute for Space Studies (GISS), NASA Goddard Space Flight Center (GSFC), Norwegian University of Science and Technology [Trondheim] (NTNU), Norwegian University of Science and Technology (NTNU), Johns Hopkins University (JHU), and University of Oxford
International audience; Atmospheric transport and suspension of dust frequently brings electrification, which may be substantial. Electric fields of 10 kV m−1 to 100 kV m−1 have been observed at the surface beneath suspended dust in the terrestrial atmosphere, and some electrification has been observed to persist in dust at levels to 5 km, as well as in volcanic plumes. The interaction between individual particles which causes the electrification is incompletely understood, and multiple processes are thought to be acting. A variation in particle charge with particle size, and the effect of gravitational separation explains to, some extent, the charge structures observed in terrestrial dust storms. More extensive flow-based modelling demonstrates that bulk electric fields in excess of 10 kV m−1 can be obtained rapidly (in less than 10 s) from rotating dust systems (dust devils) and that terrestrial breakdown fields can be obtained. Modelled profiles of electrical conductivity in the Martian atmosphere suggest the possibility of dust electrification, and dust devils have been suggested as a mechanism of charge separation able to maintain current flow between one region of the atmosphere and another, through a global circuit. Fundamental new understanding of Martian atmospheric electricity will result from the ExoMars mission, which carries the DREAMS (Dust characterization, Risk Assessment, and Environment Analyser on the Martian Surface)—MicroARES (Atmospheric Radiation and Electricity Sensor) instrumentation to Mars in 2016 for the first in situ electrical measurements.