Asymmetries observed in Saturn's magnetopause geometry
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
For over 10 years, the Cassini spacecraft has patrolled Saturn's magnetosphere and observed its magnetopause boundary over a wide range of prevailing solar wind and interior plasma conditions. We now have data that enable us to resolve a significant dawn-dusk asymmetry and find that the magnetosphere extends farther from the planet on the dawnside of the planet by 7 ± 1%. In addition, an opposing dawn-dusk asymmetry in the suprathermal plasma pressure adjacent to the magnetopause has been observed. This probably acts to reduce the size asymmetry and may explain the discrepancy between the degree of asymmetry found here and a similar asymmetry found by Kivelson and Jia (2014) using MHD simulations. Finally, these observations sample a wide range of season, allowing the “intrinsic” polar flattening (14 ± 1%) caused by the magnetodisc to be separated from the seasonally induced north-south asymmetry in the magnetopause shape found theoretically (5 ± 1% when the planet's magnetic dipole is tilted away from the Sun by 10–17°).
Date Issued
2015-09-03
Date Acceptance
2015-08-13
Citation
Geophysical Research Letters, 2015, 42 (17), pp.6890-6898
ISSN
1944-8007
Publisher
American Geophysical Union
Start Page
6890
End Page
6898
Journal / Book Title
Geophysical Research Letters
Volume
42
Issue
17
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
Geosciences, Multidisciplinary
Geology
SOLAR-WIND
BOW SHOCK
MAGNETOSPHERE
ENCELADUS
PLASMA
SHAPE
MIMI
Meteorology & Atmospheric Sciences
MD Multidisciplinary
Publication Status
Published