Electron Energization by Ion Density Enhancement in the Martian Magnetotail—MAVEN Observations
Year: 2024
Type: article
Abstract: It has been long observed at Mars that electron fluxes are enhanced during the tail current sheet crossings, of which the cause is not well understood. We use a novel approach to reveal one of the electron energization mechanisms with observations from the Mars Atmospheric and Volatile EvolutioN (MAVEN) mission. We find the field-aligned potential, derived from comparing electron distribution functions, to be approximately linearly correlated with the logarithmic values of the local total ion density. This is the expected behavior of an ambipolar electrostatic potential. The large amplitude of potential (tens to hundreds of V) is a result of both a significant density gradient (1 order of magnitude) and the high electron temperature (tens of eV) in the tail. Such a mechanism is not limited to ion density enhancements at current sheet crossings but can be present anywhere that large ion density gradients and hot electrons are present.
Source: The Astrophysical Journal
Institutions: Space Sciences Laboratory, University of California, Berkeley, University of Iowa, West Virginia University, Goddard Space Flight Center, Centre National de la Recherche Scientifique, Université Toulouse III - Paul Sabatier, Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Awards: G3029946720, G7895135561
OpenAlex ID: W4404154669