Magnetospheric Current Systems

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 118. The magnetosphere is an open system that interacts with the solar wind. In this system, solar wind energy continuously permeates different regions of the magnetosphere through electromagnetic processes, which we can well describe in terms of current systems. In fact, our ability to use various methods to study magnetospheric current systems has recently prompted significant progress in our understanding of the phenomenon. Unprecedented coverage of satellite and ground?]based observations has advanced global approaches to magnetospheric current systems, whereas advanced measurements of electromagnetic fields and particles have brought new insights about micro?]processes. Increased computer capabilities have enabled us to simulate the dynamics not only of the terrestrial magnetosphere but also the magnetospheres of other planets. Based on such developments, the present volume revisits outstanding issues about magnetospheric current systems.

Electric currents are fundamental to the structure and dynamics of space plasmas, including our own near-Earth space environment, or “geospace.”This volume takes an integrated approach to the subject of electric currents by incorporating their phenomenology and physics for many regions in one volume. It covers a broad range of topics from the pioneers of electric currents in outer space, to measurement and analysis techniques, and the many types of electric currents. First volume on electric currents in space in over a decade that provides authoritative up-to-date insight on the current status of research Reviews recent advances in observations, simulation, and theory of electric currents Provides comparative overviews of electric currents in the space environments of different astronomical bodies Electric Currents in Geospace and Beyond serves as an excellent reference volume for a broad community of space scientists, astronomers, and astrophysicists who are studying space plasmas in the solar system. Read an interview with the editors to find out more: https://eos.org/editors-vox/electric-currents-in-outer-space-run-the-show

Up to now, most studies were carried out assuming azimuthally symmetric currents, neglecting the well established longitudinal asymmetry in the geomagnetic disturbance at low- and mid-latitudes during magnetic storms. The asymmetric perturbations superposed upon a symmetric field depression has been attributed by several authors to a a longitudinally limited, partial ring current with field aligned closure through the auroral ionosphere (Cummings; Fukushima and Kamide; and references therein). It has been the objective of the research covered by this report to study the effects of such magnetospheric current systems on the propagation of cosmic ray particles through the domain of the earth's magnetosphere. The corresponding results were expected to demonstrate the significance of cosmic ray measurements as an additional tool for magnetospheric studies, especially in modeling the disturbed magnetic field in the magnetosphere. In this report, first the approach to the problem is reviewed in Section 2, and examples of the basic tools needed in the procedure are illustrated in Section 3. Then, in Section 4, the results of a simple study correlating local perturbations in the geomagnetic field with cosmic ray cutoff rigidity variations are discussed. Section 5 contains a summary of a detailed quantitative analysis on the effects of a partial ring current and of field-aligned currents on both cutoff rigidities and asymptotic directions in different latitude regions. In conclusions, the significance of the results obtained in the entire study is discussed in Section 6 for both magnetospheric and cosmic ray research.

Überblick über den aktuellen Wissensstand und künftige Forschungsrichtungen in der Magnetosphärenphysik In den sechs Jahrzehnten seit der Einführung des Begriffs ?Magnetosphäre? sind über den magnetisierten Raum, der jeden Körper in unserem Sonnensystem umgibt, viele Theorien entstanden und viele Erkenntnisse gewonnen worden. Jede Magnetosphäre ist einzigartig und verhält sich doch entsprechend den universellen physikalischen Vorgängen. Der Band ?Magnetospheres in the Solar System? enthält Beiträge von Experten für Experimentalphysik, theoretische Physik und numerische Modellierung, die einen Überblick über verschiedene Magnetosphären vermitteln, von der winzigen Magnetosphäre des Merkur bis zu den gewaltigen planetarischen Magnetosphären von Jupiter und Saturn. Das Werk bietet insbesondere: * Einen kompakten Überblick über die Geschichte der Magnetosphäre, ihre Grundsätze und Gleichungen * Eine Zusammenfassung der grundlegenden Prozesse in der Magnetospährenphysik * Instrumente und Techniken zur Untersuchung von Prozessen in der Magnetosphäre * Eine besondere Schwerpunktsetzung auf die Magnetosphäre der Erde und ihre Dynamik * Eine Darstellung der planetaren Magnetfelder und Magnetosphären im gesamten Sonnensystem * Eine Definition der künftigen Forschungsrichtungen in der Magnetosphärenphysik Die Amerikanische Geophysikalische Vereinigung fördert die wissenschaftliche Erforschung der Erde und des Weltraums zum Wohle der Menschheit. In ihren Publikationen werden wissenschaftliche Erkenntnisse veröffentlicht, die Forschern, Studenten und Fachkräften zur Verfügung stehen.

Cross-Scale Coupling and Energy Transfer in the Magnetosphere-Ionosphere-Thermosphere System provides a systematic understanding of Magnetosphere-Ionosphere-Thermosphere dynamics. Cross-scale coupling has become increasingly important in the Space Physics community. Although large-scale processes can specify the averaged state of the system reasonably well, they cannot accurately describe localized and rapidly varying structures in space in actual events. Such localized and variable structures can be as intense as the large-scale features. This book covers observations on quantifying coupling and energetics and simulation on evaluating impacts of cross-scale processes. It includes an in-depth review and summary of the current status of multi-scale coupling processes, fundamental physics, and concise illustrations and plots that are usable in tutorial presentations and classrooms. Organized by physical quantities in the system, Cross-Scale Coupling and Energy Transfer in the Magnetosphere-Ionosphere-Thermosphere System reviews recent advances in cross-scale coupling and energy transfer processes, making it an important resource for space physicists and researchers working on the magnetosphere, ionosphere, and thermosphere. Describes frontier science and major science around M-I-T coupling, allowing for foundational understanding of this emerging field in space physics Reviews recent and key findings in the cutting-edge of the science Discusses open questions and pathways for understanding how the field is evolving

Earth's Magnetosphere: Formed by the Low Latitude Boundary Layer, Second Edition, provides a fully updated overview of both historical and current data related to the magnetosphere and how it is formed. With a focus on experimental data and space missions, the book goes in depth relating space physics to the Earth’s magnetosphere and its interaction with the solar wind. Starting with Newton’s law, this book also examines Maxwell’s equations and subsidiary equations such as continuity, constitutive relations and the Lorentz transformation, Helmholtz’ theorem, and Poynting’s theorem, among other methods for understanding this interaction. This new edition of Earth’s Magnetosphere is updated with information on such topics as 3D reconnection, space weather implications, recent missions such as MMS, ionosphere outflow and coupling, and the inner magnetosphere. With the addition of end-of-chapter problems as well, this book is an excellent foundational reference for geophysicists, space physicists, plasma physicists, and graduate students alike. Offers an historical perspective of early magnetospheric research, combined with progress up to the present Describes observations from various spacecraft in a variety of regions, with explanations and discussions of each Includes chapters on prompt particle acceleration to high energies, plasma transfer event, and the low latitude boundary layer

In the past two decades a succession of direct observations by satellites, and of extensive computer simulations, has led to the realization that the polar ionosphere plays a principal role in large-scale magnetospheric processes - a manifestation of the physics linkage involved in solar-terrestrial interactions. Spatial/temporal variations in high-latitude electromagnetic phenomena, such as dynamic aurorae, electric fields and currents, have proved to be extremely complex. Now the challenge is to comprehend the vast amount of complicated measurements made in this magnetosphere-ionosphere sysstem of the Earth. This book addresses the electrical coupling between the hot, but dilute, magnetospheric plasma and the cold, but dense, plasma in the ionosphere. In five major chapters, this book presents: - basic properties of magnetosphere-ionosphere coupling; - morphology of electric fields and currents at high latitudes; - global modeling of magnetosphere-ionosphere coupling; - modeling of ionospheric electrodynamics; - current issues, such as auroral particle acceleration, substorms, penetration of high-latitude fields into low latitudes.

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.