Reconnection of Magnetic Fields


Book Description

The reconnection of magnetic fields is one of the most fascinating processes in plasma physics, responsible for phenomena such as solar flares and magnetospheric substorms. The concept of reconnection has developed through recent advances in exploring the magnetospheres of the Sun and Earth through theory, computer simulations and spacecraft observations. The great challenge in understanding it stems from balancing the large volumes of plasma and magnetic fields involved with the energy release with the physical mechanism which relies on the strongly localized behavior of charged particles. This book, edited by and with contributions from leading scientists in the field, provides a comprehensive overview of recent theoretical and observational findings concerning the physics of reconnection and the complex structures that may give rise to, or develop from, reconnection. It is intended for researchers and graduate students interested in the dynamics of plasmas.




Magnetic Reconnection


Book Description

The essential introduction to magnetic reconnection—written by a leading pioneer of the field Plasmas comprise more than 99 percent of the visible universe; and, wherever plasmas are, magnetic reconnection occurs. In this common yet incompletely understood physical process, oppositely directed magnetic fields in a plasma meet, break, and then reconnect, converting the huge amounts of energy stored in magnetic fields into kinetic and thermal energy. In Magnetic Reconnection, Masaaki Yamada offers an illuminating synthesis of modern research and advances on this important topic. Magnetic reconnection produces such phenomena as solar flares and the northern lights, and occurs in nuclear fusion devices. A better understanding of this crucial cosmic activity is essential to comprehending the universe and varied technological applications, such as satellite communications. Most of our knowledge of magnetic reconnection comes from theoretical and computational models and laboratory experiments, but space missions launched in recent years have added up-close observation and measurements to researchers’ tools. Describing the fundamental physics of magnetic reconnection, Yamada links the theory with the latest results from laboratory experiments and space-based observations, including the Magnetic Reconnection Experiment (MRX) and the Magnetospheric Multiscale (MMS) Mission. He concludes by considering outstanding problems and laying out a road map for future research. Aimed at advanced graduate students and researchers in plasma astrophysics, solar physics, and space physics, Magnetic Reconnection provides cutting-edge information on a vital area of scientific investigation.




Magnetic Reconnection


Book Description

This book provides an overview of recent research highlights in the main areas of application of magnetic reconnection (MR), including planetary, solar and magnetospheric physics and astrophysics. It describes how research on magnetic reconnection, especially concerning the Earth's magnetosphere, has grown extensively due to dedicated observations from major satellite missions such as Cluster, Double Star and Themis. The accumulated observations from these missions are being supplemented by many theoretical and modelling efforts, for which large scale computer facilities are successfully being used, and the theoretical advances are also covered in detail. Opening with an introductory discussion of some fundamental issues related to magnetic reconnection, subsequent chapters address topics including collisionless magnetic reconnection, MHD structures in 3D reconnection, energy conversion processes, fast reconnection mediated by plasmoids, rapid reconnection and magnetic field topology. Further chapters consider specific areas of application such as magnetospheric dayside and tail reconnection, comparative reconnection in planetary systems and reconnection in astrophysical systems. The book offers insight into discussions about fundamental concepts and key aspects of MR, access to the full set of applications of MR as presently known in space physics and in astrophysics, and an introduction to a new related area of study dealing with the annihilation of quantum magnetic fluxes and its implications in the study on neutron star activity. The book is aimed primarily at students entering the field, but will also serve as a useful reference text for established scientists and senior researchers.




Solar Flares and Collisions between Current-Carrying Loops


Book Description

In this volume we compare modem observations of solar flares with results from recent theoretical research and simulation studies on current-carrying loops and their interaction. These topics have undergone rapid developments in the course of recent years. Observational results by X-ray monitoring and imaging spacecraft in the seventies and by dedicated imaging instrumentation in the satellites Solar Max imum Mission and Hinotori, launched 1980 and 1981, have shown the importance of X-ray imaging for understanding the ignition processes of solar flares. Such observations, in tum, stimulated theoretical studies, centered around the flux-tube concept. The classical idea that flares originate by interaction of current-carrying loops was developed and proved to be promising. Concepts on reconnection and coalescence of flux tubes were developed, and their consequences studied. The Yohkoh spacecraft, launched 1991, showed the overwhelming importance of coro nal flux tubes and their many possible ways of interaction. Subsequent and parallel theoretical studies and simulations, differentiating between the topology of interact ing fluxtubes, demonstrated that the mutual positioning and the way of interaction are important for the subsequent processes of energy release in flares and the many associated phenomena such as the expUlsion of jets and the emission of X -ray and microwave radiation. The new developments now enable researchers to understand and classify flares in a physically significant way. Various processes of accelera tion are active in and after flares on greatly varying timescales; these can now be distinguished and explained.




Tubes, Sheets and Singularities in Fluid Dynamics


Book Description

Modern experiments and numerical simulations show that the long-known coherent structures in turbulence take the form of elongated vortex tubes and vortex sheets. The evolution of vortex tubes may result in spiral structures which can be associated with the spectral power laws of turbulence. The mutual stretching of skewed vortex tubes, when they are close to each other, causes rapid growth of vorticity. Whether this process may or may not lead to a finite-time singularity is one of the famous open problems of fluid dynamics. This book contains the proceedings of the NATO ARW and IUTAM Symposium held in Zakopane, Poland, 2-7 September 2001. The papers presented, carefully reviewed by the International Scientific Committee, cover various aspects of the dynamics of vortex tubes and sheets and of their analogues in magnetohydrodynamics and in quantum turbulence. The book should be a useful reference for all researchers and students of modern fluid dynamics.




Basic Space Plasma Physics (Revised Edition)


Book Description

This textbook begins with a description of the Earth's plasma environment, followed by the derivation of single particle motions in electromagnetic fields, with applications to the Earth's magnetosphere. Also discussed are the origin and effects of collisions and conductivities, formation of the ionosphere, magnetospheric convection and dynamics, and solar wind-magnetosphere coupling.The second half of the book presents a more theoretical foundation of plasma physics, starting with kinetic theory. Introducing moments of distribution function permits the derivation of the fluid equations, followed by an analysis of fluid boundaries, with the Earth's magnetopause and bow shock as examples, and finally, fluid and kinetic theory are applied to derive the relevant wave modes in a plasma.This revised edition seamlessly integrates new sections on magnetopause reconstruction, as well as instability theory and thermal fluctuations based on new developments in space physics. Applications such as the important problems of collisionless reconnection and collisionless shocks are covered, and some problems have also been included at the end of each chapter.




The Sun from Space


Book Description

The First Edition of The Sun from Space, completed in 1999, focused on the early accomplishments of three solar spacecraft, SOHO, Ulysses, and Yohkoh, primarily during a minimum in the Sun’s 11-year cycle of magnetic activity. The comp- hensive Second Edition includes the main ndings of these three spacecraft over an entire activity cycle, including two minima and a maximum, and discusses the signi cant results of six more solar missions. Four of these, the Hinode, RHESSI, STEREO, and TRACE missions were launched after the First Edition was either nished or nearly so, and the other two, the ACE and Wind spacecraft, extend our investigations from the Sun to its varying input to the Earth. The Second Edition does not contain simple updates or cosmetic patch ups to the material in the First Edition. It instead contains the relevant discoveries of the past decade, integrated into chapters completely rewritten for the purpose. This provides a fresh perspective to the major topics of solar enquiry, written in an enjoyable, easily understood text accessible to all readers, from the interested layperson to the student or professional.




Turbulence and Magnetic Fields in Astrophysics


Book Description

This book contains review articles of most of the topics addressed at the conf- ence on Simulations of Magnetohydrodynamic turbulence in astrophysics: recent achievements and perspectives which took place from July 2 to 6, 2001 at the Institut Henri Poincar ́e in Paris. We made the choice to publish these lectures in a tutorial form so that they can be read by a broad audience. As a result, this book does not give an exhaustive view of all the subjects addressed during the conference. The main objective of this workshop which gathered about 90 scientists from di?erent ?elds, was to present and confront recent results on the topic of t- bulence in magnetized astrophysical environments. A second objective was to discuss the latest generation of numerical codes, such as those using adaptive mesh re?nement (AMR) techniques. During a plenary discussion at the end of the workshop discussions were held on several topics, often at the heart of vivid controversies. Topics included the timescale for the dissipation of magneto-hydrodynamical (MHD) turbulence, the role of boundary conditions, the characteristics of imbalanced turbulence, the validity of the polytropic approach to Alfv ́en waves support within interst- lar clouds, the source of turbulence inside clouds devoid of stellar activity, the timescale for star formation, the Alfv ́en Mach number of interstellar gas motions, the formation process for helical ?elds in the interstellar medium. The impact of small upon large scales was also discussed.




Mechanisms of Chromospheric and Coronal Heating


Book Description

One of the great problems of astrophysics is the unanswered question about the origin and mechanism of chromospheric and coronal heating. Just how these outer stellar envelopes are heated is of fundamental importance, since all stars have hot chromospheric and coronal shells where the temperature rises to millions of degrees, comparable to the temperatures in the stars' cores. Here for the first time is a comprehensive inventory of the proposed chromospheric and coronal heating theories. The proposed heating processes are critically compared, and the observational evidence for the various mechanisms is reviewed. This is essential reading for all those working in such fields as stellar activity, radio and XUV emission, rotation, and mass loss, for whom a detailed and consistent presentation of our knowledge of chromospheric and coronal heating mechanisms is urgently needed.