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MAVEN observations of energy‐time dispersed electron signatures in Martian crustal magnetic fields
Author(s) -
Harada Y.,
Mitchell D. L.,
Halekas J. S.,
McFadden J. P.,
Mazelle C.,
Connerney J. E. P.,
Espley J.,
Brain D. A.,
Larson D. E.,
Lillis R. J.,
Hara T.,
Livi R.,
DiBraccio G. A.,
Ruhunusiri S.,
Jakosky B. M.
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl067040
Subject(s) - martian , mars exploration program , electron , atmosphere of mars , magnetic field , physics , geophysics , atmosphere (unit) , dispersion (optics) , flux (metallurgy) , computational physics , astrobiology , materials science , nuclear physics , meteorology , quantum mechanics , optics , metallurgy
Energy‐time dispersed electron signatures are observed by the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission in the vicinity of strong Martian crustal magnetic fields. Analysis of pitch angle distributions indicates that these dispersed electrons are typically trapped on closed field lines formed above strong crustal magnetic sources. Most of the dispersed electron signatures are characterized by peak energies decreasing with time rather than increasing peak energies. These properties can be explained by impulsive and local injection of hot electrons into closed field lines and subsequent dispersion by magnetic drift of the trapped electrons. In addition, the dispersed flux enhancements are often bursty and sometimes exhibit clear periodicity, suggesting that the injection and trapping processes are intrinsically time dependent and dynamic. These MAVEN observations demonstrate that common physical processes can operate in both global intrinsic magnetospheres and local crustal magnetic fields.