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Warm flux tubes in the E‐ring plasma torus: Initial Cassini magnetometer observations
Author(s) -
Leisner J. S.,
Russell C. T.,
Khurana K. K.,
Dougherty M. K.,
André N.
Publication year - 2005
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 - 10.1029/2005gl022652
Subject(s) - magnetosphere , jovian , physics , torus , plasma sheet , saturn , flux (metallurgy) , plasma , diamagnetism , magnetic flux , magnetometer , magnetic field , magnetosphere of saturn , astrophysics , jupiter (rocket family) , poynting vector , geophysics , magnetopause , astronomy , planet , materials science , geometry , mathematics , quantum mechanics , metallurgy , space shuttle
Initial Cassini magnetometer observations in the E‐ring plasma torus reveal the presence of previously unreported diamagnetic decreases in the magnetic field. The decrease in magnetic pressure on these flux tubes implies the presence of additional plasma energy densities up to 1 keV/cm 3 . They are less stretched than surrounding flux tubes suggesting the centrifugal force acting on them is less, possibly because they have a lower mass content or lower azimuthal velocity than their neighbors. Outward from these isolated tubes, at about 6 Saturn radii, an irregular transition from predominantly cool to predominantly warm flux tubes is observed. A similar boundary is observed in the jovian magnetosphere at the outer edge of the Io torus. Both the saturnian and jovian boundaries are candidates for the interchange instability but other processes may also be acting. ULF waves are associated with some, but not all, of these flux tubes.