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Alfvén vortices in Saturn's magnetosheath: Cassini observations
Author(s) -
Alexandrova O.,
Saur J.
Publication year - 2008
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 - 10.1029/2008gl034411
Subject(s) - magnetosheath , physics , vortex , bow shock (aerodynamics) , magnetic field , saturn , plasma , bow wave , shock wave , solar wind , geophysics , astrophysics , mechanics , magnetopause , planet , quantum mechanics
First signatures of Alfvén vortices in the Kronian magnetosheath are presented. An Alfvén vortex is a non‐linear bi‐dimensional magnetic structure associated with sheared magnetic field and velocity perturbations, propagating obliquely to the external magnetic field direction. Such structures have been recently discovered by Cluster in Earth's magnetosheath downstream of a quasi‐perpendicular bow‐shock at scales close to 10 c / ω pi (where c is the speed of light and ω pi the ion plasma frequency). The presence of Alfvén vortices downstream of a quasi‐perpendicular bow‐shock of Saturn with comparable scales to the ones at Earth indicates the universality of this phenomenon. It suggests that such non‐linear structures are an inherent property of plasma flow downstream of collisionless shock waves, which can have broad astrophysical applications.