The Near-Saturn Magnetic Field Environment

ISBN-13: 9783319492919 / Angielski / Twarda / 2016 / 97 str.

Ali Haidar Sulaiman

Opis

This thesis focuses on the very high Mach number shock wave that is located sunward of Saturn's strong magnetic field in the continuous high-speed flow of charged particles from the Sun (the solar wind).

Spis treści

Introduction to Space Plasmas.- Definition and Characteristics of Plasmas.- Plasma vs Neutral Gas.- Single Particle Motion.- Magnetohydrodynamics.- The Induction Equation and Flux Freezing.- Kinetic Description.- Applicability of MHD and Kinetic Simulations of Plasmas.- Collisionless MHD Waves.- Fundamentals of Shock Waves.- Collisionless Shock Waves.- State Variables and Control Parameters.- Criticality.- Particle Dynamics and the DC Electric Field.- Shock Frames of Reference.- Quasi-parallel Shocks.- The Sun-Saturn Connection.- The Solar Wind.- Properties at 10 AU.- The Kronian Environment.- Spacecraft Encounters.- Saturn’s Magnetosphere.- Dungey vs Vasyliunas Cycles.- The KSM Coordinate System.- Cassini Observations of Saturn’s Dayside Environment.- Motivation of this Thesis.- Spacecraft and Instrumentation.- The Cassini-Huygens Spacecraft.- Cassini Fluxgate Magnetometer.- Calibration.- Cassini Radio and Plasma Wave Science (RPWS) Instrument.- Cassini Ion Mass Spectrometer (CAPS/IMS).- Magnetic Field Characterisation of Saturn’s Bow Shock.- Introduction.- Size and Shape.- Determination of the Shock Normal.- Saturn as a Unique Laboratory for Collisionless Shocks.- Scope and Limitations of this Chapter.- Characterisation of Saturn’s Bow Shock.- Determination of the Alfvén Mach Number.- Parameter Space.- Shock Relative Overshoot and Variability.- Conclusion.- Quasi-perpendicular High Mach Number Collisionless Shocks.- Introduction.- Method.- Determination of the Foot Length and Shock Speed.- Observations.- Results and Discussion.- An Attempt to Reconcile with β.- Conclusion.- The Magnetic Structure of Saturn’s Magnetosheath.- Introduction.- Observations.- Data Selection.- Upstream Conditions and the Overall Configuration of the Magnetic Field in Saturn’s Magnetosheath.- Results.- MHD Simulations.- Correspondence between observations and predictive model.- Discussion.- Summary and Perspective.- 

Bibliography 

O autorze

Dr. Sulaiman graduated from Imperial College London with a Masters in Aeronautical Engineering with first class honors. He holds a Ph.D. in Space Physics at Imperial College London under Professor Michele Dougherty FRS. He is currently a postdoctoral scholar at the University of Iowa.

Blurb

This thesis focuses on the very high Mach number shock wave that is located sunward of Saturn's strong magnetic field in the continuous high-speed flow of charged particles from the Sun (the solar wind). The author exploits the fact that the Cassini spacecraft is the only orbiter in a unique parameter regime, far different from the more familiar near-Earth space, to provide in-situ insights into the unreachable exotic regime of supernova remnants. This thesis bridges the gap between shock physics in the Solar System and the physics of ultra-high Mach number shocks around the remnants of supernova explosions, since to date research into the latter has been restricted to theory, remote observations, and simulations.