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Saturn's periodic magnetic field perturbations caused by a rotating partial ring current
Author(s) -
Brandt P. C.,
Khurana K. K.,
Mitchell D. G.,
Sergis N.,
Dialynas K.,
Carbary J. F.,
Roelof E. C.,
Paranicas C. P.,
Krimigis S. M.,
Mauk B. H.
Publication year - 2010
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 - 10.1029/2010gl045285
Subject(s) - physics , saturn , plasma , magnetosphere , magnetic field , ring current , ion , atomic physics , energetic neutral atom , spectrometer , atmospheric pressure plasma , plasma sheet , computational physics , astrophysics , optics , planet , nuclear physics , quantum mechanics
We demonstrate that the periodic magnetic field perturbations as observed from Cassini are caused by the plasma pressure of the energetic (>2 keV) particle distributions that are periodically injected and subsequently drift around Saturn. Plasma pressures inferred from the Cassini Plasma Spectrometer (CAPS) (<2 keV) and the Magnetospheric Imaging Instrument (MIMI) (>2 keV) are used to compute the three‐dimensional pressure‐driven currents and their associated magnetic field perturbations. The distribution of the “hot” (>2 keV) plasma pressure is derived from Energetic Neutral Atom (ENA) images obtained by the Ion Neutral Camera (INCA) and in‐situ spectral measurements. The radial profile of “cold” (<2 keV) plasma pressure is obtained from statistical studies and is assumed to be azimuthally symmetric.