Internally driven large-scale changes in the size of Saturn's magnetosphere
File(s)
Author(s)
Type
Journal Article
Abstract
Saturn's magnetic field acts as an obstacle to solar wind flow, deflecting plasma around the planet and forming a cavity known as the magnetosphere. The magnetopause defines the boundary between the planetary and solar dominated regimes, and so is strongly influenced by the variable nature of pressure sources both outside and within. Following from Pilkington et al. (2014), crossings of the magnetopause are identified using 7 years of magnetic field and particle data from the Cassini spacecraft and providing unprecedented spatial coverage of the magnetopause boundary. These observations reveal a dynamical interaction where, in addition to the external influence of the solar wind dynamic pressure, internal drivers, and hot plasma dynamics in particular can take almost complete control of the system's dayside shape and size, essentially defying the solar wind conditions. The magnetopause can move by up to 10–15 planetary radii at constant solar wind dynamic pressure, corresponding to relatively “plasma-loaded” or “plasma-depleted” states, defined in terms of the internal suprathermal plasma pressure.
Date Issued
2015-09-10
Date Acceptance
2015-07-26
Citation
Journal of Geophysical Research: Space Physics, 2015, 120 (9), pp.7289-7306
ISSN
2169-9402
Publisher
American Geophysical Union
Start Page
7289
End Page
7306
Journal / Book Title
Journal of Geophysical Research: Space Physics
Volume
120
Issue
9
Copyright Statement
© 2015 The Authors.
This is an open access article under the
terms of the Creative Commons
Attribution License, which permits use,
distribution and reproduction in any
medium, provided the original work is
properly cited.
This is an open access article under the
terms of the Creative Commons
Attribution License, which permits use,
distribution and reproduction in any
medium, provided the original work is
properly cited.
License URL
Sponsor
Science and Technology Facilities Council (STFC)
The Royal Society
Science and Technology Facilities Council
Grant Number
ST/K001051/1
RP140004
ST/N002776/1
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
Saturn
magnetosphere
solar wind
plasma
magnetopause
SOLAR-WIND
BOW SHOCK
JOVIAN MAGNETOPAUSE
OUTER PLANETS
HOT PLASMA
MODEL
ENCELADUS
PARTICLES
JUPITER
VOYAGER
Publication Status
Published