Despite the plethora of monographs published in recent years, few cover recent progress in magnetospheric physics in broad areas of research. While a topical focus is important to in-depth views at a problem, a broad overview of our field is also needed. The volume answers to the latter need. With the collection of articles written by leading scientists, the contributions contained in the book describe latest research results in solar wind-magnetosphere interaction, magnetospheric substorms, magnetosphere-ionosphere coupling, transport phenomena in the plasma sheet, wave and particle dynamics in the ring current and radiation belts, and extra-terrestrial magnetospheric systems. In addition to its breadth and timeliness, the book highlights innovative methods and techniques to study the geospace.

An investigation is presented of certain aspects of those gyroresonance interactions which take place between very low frequency VLF electromagnetic waves and charged particle fluxes in the earth's outer ionosphere. These interactions, in which significant amounts of energy can be exchanged between the particle's kinetic energy form and the wave electromagnetic-energy form, are thought to be of importance with respect to the dynamical properties of the earths' outer ionosphere. Specifically two problems are considered. The first problem involves the stability of the outer ionosphere plasma to whistler-mode waves under conditions in which high energy electron fluxes permeate this plasma. The second problem involves the feasibility of the creation or depletion of an artificial radiation belt utilizing the geocyclotron gyroresonance interaction in order to transfer energy between man-made waves and relativistic electrons trapped in the outer ionosphere by the earths' magnetic field near the magnetic equatorial plane.

Abstract: The goals of this dissertation are: (1) to understand the physics describing the structure and dynamics of magnetic field configurations in Earth's inner magnetosphere; (2) to assess the performance of data-based and physics-based global magnetospheric models under various conditions; and (3) to quantify the responses of global magnetic and electric fields to solar wind variations, and ultimately their effects on radial transport of radiation belt electrons. The radiation belt charged particle environment, the relativistic electrons in particular, changes by orders of magnitude on a variety of time scales in a complicated fashion. In order to understand and model the dynamic behavior of radiation belt electrons, we first need global, realistic, self-consistent, and time-dependent magnetospheric models. Therefore, we compare state-of-the-art empirical Tsyganenko models and Lyon-Fedder-Mobarry (LFM) physics-based code predictions with geosynchronous measurements to assess their performance and quantify the field configurations and fluctuations in the inner magnetosphere. The Tsyganenko storm model best predicts the large-scale field magnitude for all geomagnetic conditions, but fails to reproduce small-scale wave fields. On the other hand, the LFM code reproduces both the field configurations and ultra-low-frequency (ULF) waves during non-storm intervals. Next, we simulate the dynamics of radiation belt electrons using global magnetic and electric fields from the LFM code, driven by idealized solar wind over a range of velocities. We follow the trajectories of electrons, starting at different local times and radii for the same first adiabatic invariant, to understand their transport and energization through collective wave-particle interactions. Finally, we quantify the ULF wave effects on radiation belt electrons by calculating the radial diffusion coefficients from the LFM simulation results. The derived coefficients as a function of solar wind velocity, of 10 -4 to 1 day -1 in the outer electron belt, are comparable to observational results after normalizing for wave power. Using this method, we conclude that diffusive electron transport is well simulated for various solar wind conditions and geomagnetic activity levels, a significant step toward quantitative understanding of the complex, dynamical radiation belt environment.

This contract funded a three year study of wave particle interactions and substorm dynamics in the inner magnetosphere. We completed the first ground/satellite study of ion cyclotron waves generated near the plasmapause. We published several examples of waves observed simultaneously near the equator at L=4 by the DE 1 spacecraft on the ground. In three cases correlation analysis yielded estimates of wave group delay between the equatorial source region and the ground. Model calculations that used measured plasma parameters agreed with observational estimates. Among substorm related work, we extended an earlier study of pi2 signatures to lower latitudes to show that substorm onset signatures broaden in longitudinal extent with decreasing latitude. We showed that a pi2-based substorm detector would be a more reliable tool than one based on the AL index, and we developed and tested a simple pi2 index. The results showed that a more sophisticated pi2 index would result in fewer false detections. We also formulated and began testing a new hypothesis on the triggering of substorms.

The book provides an extensive theoretical treatment of whistler-mode propagation, instabilities and damping in a hot, anisotropic and collisionless plasma. Most of the results are original and have never been published in a monograph on a similar subject before.