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Venus nightside ionospheric holes: The signatures of parallel electric field acceleration regions?
Author(s) -
Grebowsky J. M.,
Curtis S. A.
Publication year - 1981
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 - 10.1029/gl008i012p01273
Subject(s) - venus , ionosphere , physics , electric field , geophysics , atmosphere of venus , field line , electron , plasma , magnetic field , atmospheric sciences , computational physics , astrobiology , quantum mechanics
Recent observations by the instruments onboard the Pioneer Venus spacecraft have revealed the existence of "holes" or regions of density depletion in the nightside Venus ionosphere associated with regions of radial magnetic fields. The properties of the electrons within the core of these holes are suggestive of an acceleration process along the magnetic field lines as are the Venera 9 and 10 observations of energetic ions in the Venus tail. Given the observational information, we attribute these Venusian plasma depletions to the presence of parallel electric fields similar to those observed in the terrestrial auroral ionosphere. The resulting electric field accelerates electrons down the field lines producing heating of the depleted thermal electron population within the hole and production of ionization below the hole. Simultaneously ionospheric ions are accelerated outward toward the plasmasheet.