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Observations of Continuous Quasiperiodic Auroral Pulsations on Saturn in High Time-Resolution UV Auroral Imagery
Badman, S. V.; Yao, Z. H.; Bader, A. +2 more
Saturn's aurora represents the ionospheric response to plasma processes occurring in the planet's entire magnetosphere. Short-lived ∼1-hr quasiperiodic high-energy electron injections, frequently observed in in situ particle and radio measurements, should therefore entail an associated flashing auroral signature. This study uses high time-resoluti…
Can Reconnection be Triggered as a Solar Wind Directional Discontinuity Crosses the Bow Shock? A Case of Asymmetric Reconnection
Gunell, H.; Hamrin, M.; Vaivads, A. +7 more
Here we present some unique observations of reconnection at a quasi-perpendicular bow shock as an interplanetary directional discontinuity (DD) is crossing it simultaneously with the Magnetospheric Multiscale (MMS) mission. There are no burst data, but available data show indications of ongoing reconnection at the shock southward of MMS: a bifurca…
Observations of Asymmetric Lobe Convection for Weak and Strong Tail Activity
Østgaard, N.; Tenfjord, P.; Reistad, J. P. +6 more
In this study we use high-quality convection data from the Electron Drift Instrument on board Cluster to investigate how near-Earth tail activity affects the average convection pattern in the magnetotail lobes when the interplanetary magnetic field has a dominating east-west (By) component. Two different proxies have been used to repres…
Equatorial Propagation of the Magnetosonic Mode Across the Plasmapause: 2-D PIC Simulations
Boardsen, Scott A.; Liu, Kaijun; Denton, Richard E. +2 more
Recent studies have indicated that fast magnetosonic waves (also referred to as equatorial noise) excited far outside the plasmapause cannot propagate deep into the plasmasphere because of the preferential azimuthal propagation of the waves at the source region. Since conditions in the low-density plasma trough are typically favorable for the wave…
Saturn's Plasmapause: Signature of Magnetospheric Dynamics
Coates, A. J.; Thomsen, M. F.
We explore the paradigm that Saturn's plasmapause marks the boundary between the magnetic flux tubes that have been circulating around the planet for some time, accumulating a dense load of Enceladus-sourced material, and those that have recently undergone tail reconnection, shedding the bulk of the cold plasma and retaining a more tenuous, heated…
Earth's Bow Shock: A New Three-Dimensional Asymmetric Model With Dipole Tilt Effects
Wang, M.; Ma, X.; Zhou, Y. +3 more
Using the bow shock crossing events from four spacecraft: IMP 8, Geotail, Magion-4, and Cluster 1, a new three-dimensional asymmetric bow shock model is constructed. The model is parameterized by the solar wind dynamic pressure, the interplanetary magnetic field, magnetosonic Mach number, solar wind β, and the Earth's dipole tilt angle. It is show…
The Structure of Planetary Period Oscillations in Saturn's Equatorial Magnetosphere: Results From the Cassini Mission
Wahlund, J. -E.; Andrews, D. J.; Cowley, S. W. H. +4 more
Saturn's magnetospheric magnetic field, planetary radio emissions, plasma populations, and magnetospheric structure are all known to be modulated at periods close to the assumed rotation period of the planetary interior. These oscillations are readily apparent despite the high degree of axisymmetry in the internally produced magnetic field of the …
Kinetic Analysis of the Energy Transport of Two-Flow Components in the Plasma Sheet
Cao, Jin-Bin; Ren, Ganming; Ma, Yuduan
Satellite observations indicate that multiple components often exist in the plasma sheet, particularly during impulsive fast flow events. In this paper, we perform a kinetic analysis of the energy transport of plasma sheet ion flow using a model of two-component plasma sheet ion flows (Background convection flow represented by subscript "b" and Fa…
Field-Aligned Structures of the Poloidal-Mode ULF Wave Electric Field: Phase Relationship Implications
Zong, Q. G.; Ren, Jie; Zhou, X. Z. +2 more
Spacecraft observations within recent decades have demonstrated that ultralow frequency (ULF) waves play an important role in the dynamics of Earth's magnetosphere through drift and/or drift-bounce resonance with different particle species. The phase relationship between resonant particles and waves can help us understand the wave-particle interac…
Local Time Variation in the Large-Scale Structure of Saturn's Magnetosphere
Dougherty, M. K.; Arridge, C. S.; Guio, P. +3 more
The large-scale structure of Saturn's magnetosphere is determined by internal and external factors, including the rapid planetary rotation rate, significant internal hot and cold plasma sources, and varying solar wind pressure. Under certain conditions the dayside magnetospheric magnetic field changes from a dipolar to more disk-like structure, du…