Download or read book A Model of the Plasma Sheet in the Earth s Magnetosphere written by David Wallace Forslund and published by . This book was released on 1969 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Empirical Modeling of 3D Plasma Pressure and Magnetic Field Structures in the Earth s Plasma Sheet written by Chao Yue and published by . This book was released on 2015 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ions and electrons in the nightside magnetosphere, driven by the dawn-to-dusk convection electric field, flow earthward and are energized. As a result, plasma pressure is enhanced and magnetic field configuration becomes more stretched, forming the necessary conditions for the development of substorms. Determining the physical processes leading to the changes of the plasma and magnetic field configurations, as well as the processes resulting from the configuration variations, is thus crucial to understanding substorms. Accurate evaluation of these processes, including formation of field-aligned currents (FACs), isotropization by current sheet scattering, and some localized instabilities that may responsible for substorm onset, relies on knowing the realistic 3 dimensional (3D) magnetic field configurations, which cannot be provided by current available empirical models with sufficient accuracy or as a function of growth phase development. Therefore, we have developed a 3D force-balanced empirical substorm growth phase magnetic field model, which allows us to investigate the evolution of these configurations during the substorm growth phase and evaluate the physical processes governing the configuration changes. Here, we first statistically analyzed the growth phase pressures using Geotail and THEMIS data, and identified three primary factors causing the growth phase pressure change: solar wind dynamic pressure (PSW), energy loading, and sunspot number. We then constructed a 2D equatorial empirical pressure model and an error model in the near Earth plasma sheet (r 20 RE) using the Support Vector Regression Machine (SVRM) with the three factors as input. The model predicts the plasma sheet pressure accurately with median errors of 5%, and the predicted pressure gradients agree reasonably well with observed gradients obtained from two-probe measurements. The model shows that pressure increases linearly as PSW increases, while the pressure responses to energy loading and sunspot number are nonlinear. From these model pressure distributions, we were able to establish a realistic 3D growth phase magnetic field configurations that satisfy the physical constraint of force balance with the plasma pressures using a 3D magnetic field model [Zaharia, 2008]. The force-balanced magnetic field configuration shows that Bz decreases in the near Earth region and increases in the tail due to an increasing perpendicular current peaking at the earthward edge of the plasma sheet. The current peak moves towards the Earth as energy loading increases, indicating earthward penetrating of the plasma sheet. Meanwhile, positive dBz/dz is found to develop late in the growth phase, but a Bz minimum at the equator does not form, unlike the prediction by Saito et al. [2010]. The perpendicular current peaks off the equator plane and its peak moves towards the equatorial plane as the growth phase evolves, indicating the thinning of current sheet. In addition, there are typical Region-1 FACs around 12 to 20 RE at the beginning of substorm growth phase and they gradually evolve to Region-2 FACs in the late growth phase with their earthward boundary moving to smaller r. The model magnetic fields agree quantitatively well with observed fields. The magnetic field is substantially more stretched under higher PSW while the dependence on sunspot number is non-linear and less substantial. The excellent agreements between the model results and observations give us confidence that the realistic model can be used at the first time to understand the pressure and magnetic field changes observed during a substorm event by providing accurate evaluations of the effects of energy loading and PSW, as well as the temporal and spatial effects along a spacecraft trajectory. By applying our modeling to a substorm event, we found that the equatorward moving of proton aurora during the growth phase is mainly due to continuous stretching of magnetic field lines, and the ballooning instability is more favorable at late growth phase around midnight tail where there is a localized plasma beta peak. Furthermore, the equatorial mapping of the breakup auroral arc is X ~ -14 RE near midnight, coinciding with the location of the maximum growth rate for ballooning instability.
Download or read book Plasma Waves in the Magnetosphere written by A.D.M. Walker and published by Springer. This book was released on 1993-03-30 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a study of plasma waves which are observed in the earth's magnetosphere. The emphasis is on a thorough, but concise, treatment of the necessary theory and the use of this theory to understand the manifold varieties of waves which are observed by ground-based instruments and by satellites. We restrict our treatment to waves with wavelengths short compared with the spatial scales of the background plasma in the mag netosphere. By so doing we exclude large scale magnetohydrodynamic phenomena such as ULF pulsations in the Pc2-5 ranges. The field is an active one and we cannot hope to discuss every wave phenomenon ever observed in the magnetosphere! We try instead to give a good treatment of phenomena which are well understood, and which illustrate as many different parts of the theory as possible. It is thus hoped to put the reader in a position to understand the current literature. The treatment is aimed at a beginning graduate student in the field but it is hoped that it will also be of use as a reference to established workers. A knowledge of electromagnetic theory and some elementary plasma physics is assumed. The mathematical background required in cludes a knowledge of vector calculus, linear algebra, and Fourier trans form theory encountered in standard undergraduate physics curricula. A reasonable acquaintance with the theory of functions of a complex vari able including contour integration and the residue theorem is assumed.
Download or read book Simulating the Interplay Between Plasma Transport Electric Field and Magnetic Field in the Near Earth Nightside Magnetosphere written by Malamati Gkioulidou and published by . This book was released on 2012 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: The convection electric field resulting from the coupling of the Earth's magnetosphere with the solar wind and interplanetary magnetic field (IMF) drives plasma in the tail plasma sheet earthward. This transport and the resulting energy storage in the near Earth plasma sheet are important for setting up the conditions that lead to major space weather disturbances, such as storms and substorms. Penetration of plasma sheet particles into the near-Earth magnetosphere in response to enhanced convection is crucial to the development of the Region 2 field-aligned current system and large-scale magnetosphere-ionosphere (M-I) coupling, which results in the shielding of the convection electric field. In addition to the electric field, plasma transport is also strongly affected by the magnetic field, which is distinctly different from dipole field in the inner plasma sheet and changes with plasma pressure in maintaining force balance. The goal of this dissertation is to investigate how the plasma transport into the inner magnetosphere is affected by the interplay between plasma, electric field and magnetic field. For this purpose, we conduct simulations using the Rice Convection Model (RCM), which self-consistently calculates the electric field resulting from M-I coupling. In order to quantitatively evaluate the interplay, we improved the RCM simulations by establishing realistic plasma sheet particle sources, by incorporating it with a modified Dungey force balance magnetic field solver (RCM-Dungey runs), and by adopting more realistic electron loss rates. We found that plasma sheet particle sources strongly affect the shielding of the convection electric field, with a hotter and more tenuous plasma sheet resulting in less shielding than a colder and denser one and thus in more earthward penetration of the plasma sheet. The Harang reversal, which is closely associated with the shielding of the convection electric field and the earthward penetration of low-energy protons, is found to be located at lower latitudes and extend more dawnward for a hotter and more tenuous plasma sheet. In comparison with simulation runs under an empirical but not force balance magnetic field from the Tsyganenko 96 model, the simulation results show that transport under force-balanced magnetic field results in weaker pressure gradients and thus weaker R2 FAC in the near-earth region, weaker shielding of the penetration electric field and, as a result, more earthward penetration of plasma sheet protons and electrons with their inner edges being closer together and more azimuthally symmetric. To evaluate the effect of electron loss rate on ionospheric conductivity, a major contributing factor to M-I coupling, we run RCM-Dungey with a more realistic, MLT dependent electron loss rate established from observed wave activity. Comparing our results with those using a strong diffusion everywhere rate, we found that under the MLT dependent loss rate, the dawn-dusk asymmetry in the precipitating electron energy fluxes agrees better with statistical DMSP observations. The more realistic loss rate is much weaker than the strong diffusion limit in the inner magnetosphere. This allows high-energy electrons in the inner magnetosphere to remain much longer and produce substantial conductivity at lower latitudes. The higher conductivity at lower latitudes under the MLT dependent loss rate results in less efficient shielding in response to an enhanced convection electric field, and thus to deeper penetration of the ion plasma sheet into the inner magnetosphere than under the strong diffusion everywhere rate.
Download or read book Physics Of Space Plasmas written by George K Parks and published by CRC Press. This book was released on 2019-08-21 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook was developed to provide seniors and first-year graduate students in physical sciences with a general knowledge of electrodynamic phenomena in space. Since the launch of the first unmanned satellite in 1957, experiments have been performed to study the behavior of electromagnetic fields and charged particles. There is now a considerable amount of data on hand, and many articles, including excellent review articles, have been written for the specialists. However, for students, new researchers, and non-specialists, a need still exists for a book that integrates these observations in a coherent way. This book is an attempt to meet that need by using the theory of classical electrodynamics to unify space observations. The contents of this book are based on classroom notes developed for an introductory space physics course that the author has taught for many years at the University of Washington. Students taking the course normally have had an undergraduate course in electricity and magnetism but they come with very little knowledge about space.
Download or read book Solar System Plasmas and Fields written by J. Lemaire and published by Pergamon. This book was released on 1982 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetospheric Plasma Physics The Impact of Jim Dungey s Research written by David Southwood and published by Springer. This book was released on 2015-08-20 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book makes good background reading for much of modern magnetospheric physics. Its origin was a Festspiel for Professor Jim Dungey, former professor in the Physics Department at Imperial College on the occasion of his 90th birthday, 30 January 2013. Remarkably, although he retired 30 years ago, his pioneering and, often, maverick work in the 50’s through to the 70’s on solar terrestrial physics is probably more widely appreciated today than when he retired. Dungey was a theoretical plasma physicist. The book covers how his reconnection model of the magnetosphere evolved to become the standard model of solar-terrestrial coupling. Dungey’s open magnetosphere model now underpins a holistic picture explaining not only the magnetic and plasma structure of the magnetosphere, but also its dynamics which can be monitored in real time. The book also shows how modern day simulation of solar terrestrial coupling can reproduce the real time evolution of the solar terrestrial system in ways undreamt of in 1961 when Dungey’s epoch-making paper was published. Further contributions on current Earth magnetosphere research and space plasma physics included in this book show how Dungey’s basic ideas have remained explanative 50 years on. But the Festspiel also introduced some advances that possibly Dungey had not foreseen. One of the contributions presented in this book is on the variety of magnetospheres of the solar system which have been seen directly during the space age, discussing the variations in spatial scale and reconnection time scale and comparing them in respect of Earth, Mercury, the giant planets as well as Ganymede.
Download or read book Physics of the Magnetosphere written by R.L. Carovillano and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 693 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph is based upon the proceedings of the Summer Institute, Physics of the Magnetosphere, held on the Boston College campus, lune 19-28, 1967. The pro gram consisted of invited speakers selected by the Editors. An attempt was made to provide comprehensive treatment of all topics of primary relevance to magneto spheric physics, but, of course, some areas received greater coverage than others. The first portion of the conference consisted of tutoriallectures, four each, by five distinguished scientists, and these are presented in Part I of the monograph. The artides appearing in Part I were prepared by the Editors from tapes of the actual lectures. Preliminary manuscripts were prepared and each tutoriallecturer was given the opportunity to make changes or improvements that were incorporated into the final manuscript. H. R. Radoski prepared the lectures of Professor Helliwell; 1. F. McClay prepared the lectures of Professor Dessler and the first two of Professor Dungey; and the remaining lectures of Professors Dungey, Parker, and Van Allen were prepared by me. An effort was made for the most part to write each manuscript in the style of the lectures, but the incongruities of spoken English and the number of scribes in the kitchen undoubtedly limited our success. Everyone knows that English is written far better than it is spoken, although for some reason the spoken word is more dear.
Download or read book Particles and Fields in the Magnetosphere written by Billy McCormac and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the lectures presented at the Advanced Study Institute, 'Earth's Particles and Fields, 1969', which was held at the University of California, Santa Barbara, during the period August 4 through 15, 1969. One hundred seventy persons from twelve different countries attended the Institute. The authors and the publisher have made a special effort for rapid publication of an up-to-date status of the particles and fields in the earth's magnetosphere, which is an ever changing research area. Special thanks are due to the lecturers for their diligent preparation and excellent presentations. The individual lectures and the published papers were deliberately limited; the author's cooperation in conforming to these specifications is greatly appreciated. The contents of the book are organized by subject area rather than in the order in which papers were presented during the Institute. Many thanks are due to Drs. Kinsey Anderson, Sam Bame, Leverett Davis, Gilbert Mead, Harry Elliot, Kenneth Behannon, Reimar Lust, A. W. Schardt, Carl-Gunne Eilthammar, and Martin Walt who served as session chairmen during the Institute and contributed greatly to its success by skillfully directing the discussion period in a stimulating manner after each lecture. Dr. Martin Walt and the Summary Panel worked hard to prepare an excellent summary of various aspects of particles and fields in the magnetosphere at the end of the Institute.
Download or read book Examples of Plasma Flows Within the Earth s Magnetosphere written by Louis A. Frank and published by . This book was released on 1975 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examples of observed flows of plasmas in the dayside magnetosphere near the magnetopause, within the ring current in the local-evening sector, and at two positions simultaneously in the plasma sheet are presented. These measurements were gained with LEPEDEA plasma instruments on the satellites IMP's -6 and -7. Flow velocities inside the magnetopause in the dayside magnetosphere are typically 25 to 75 km/sec, and are directed generally parallel to the tangent to the nearby magnetopause with a small component directed into this boundary. Bulk flow speeds within the ring current ranged from the instrument threshold of about 20 km/sec to speeds of 50 km/sec. Strong tailward 'jetting' of plasmas, in the range of 200 to 300 km/sec, at geocentric radial distances about 35 (R sub E) in the plasma sheet is found to be often associated with the occurrence of magnetic substorms.
Download or read book Dawn Dusk Asymmetries in Planetary Plasma Environments written by Stein Haaland and published by John Wiley & Sons. This book was released on 2017-10-09 with total page 915 pages. Available in PDF, EPUB and Kindle. Book excerpt: DawnDusk Asymmetries in Planetary Plasma Environments Dawn-dusk asymmetries are ubiquitous features of the plasma environment of many of the planets in our solar system. They occur when a particular process or feature is more pronounced at one side of a planet than the other. For example, recent observations indicate that Earth's magnetopause is thicker at dawn than at dusk. Likewise, auroral breakups at Earth are more likely to occur in the pre-midnight than post-midnight sectors. Increasing availability of remotely sensed and in situ measurements of planetary ionospheres, magnetospheres and their interfaces to the solar wind have revealed significant and persistent dawn-dusk asymmetries. As yet there is no consensus regarding the source of many of these asymmetries, nor the physical mechanisms by which they are produced and maintained. Volume highlights include: A comprehensive and updated overview of current knowledge about dawn-dusk asymmetries in the plasma environments of planets in our solar system and the mechanisms behind them Valuable contributions from internationally recognized experts, covering both observations, simulations and theories discussing all important aspects of dawn-dusk asymmetries Space weather effects are caused by processes in space, mainly the magnetotail, and can be highly localized on ground. Knowing where the source, i.e., where dawn-dusk location is will allow for a better prediction of where the effects on ground will be most pronounced Covering both observational and theoretical aspects of dawn dusk asymmetries, Dawn-Dusk Asymmetries in Planetary Plasma Environments will be a valuable resource for academic researchers in space physics, planetary science, astrophysics, physics, geophysics and earth science.
Download or read book Magnetic Field and Plasma Flow Fluctuations in the Near earth Plasma Sheet written by Elena Neagu and published by . This book was released on 2001 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics of the Hot Plasma in the Magnetosphere written by Bengit Hultqvist and published by Springer. This book was released on 1975-11 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nobel Symposium No. 30 on the Physics of the Hot Plasma in the Magnetosphere was held at Kiruna Geophysical Institute, Kiruna, Sweden from April 2-4, 1975. Some 40 leading experts from America, USSR, and Western Europe attended the Symposium. The purpose of the meeting was to review and discuss the physics of the hot plasma in the magnetosphere with special empha sis on unsolved problems on which attention needs to be focused during the International Magnetospheric Study 1976-1978. The field is very extensive and complete coverage of all aspects was of course not possible. The radiation belts proper were, for instance, not covered. There were no formal contributed papers, but much time was devoted to discussion. These proceedings contain all review papers except the one by R.Z. Sagdeev. They are ordered by subject, starting, after the introductory lecture, with the problem of how the plasma enters the magnetosphere and ending with the question of the interaction with the ionosphere. The Organizing Committee for the symposium was composed of the following Swedish scientists: E.-A. Brunberg, C.G. Fa1thammar, I. Hu1then, B. Hu1tqvist (chairman), L. Stenf10, and H. Wilhe1msson. The Symposium was financed by the Nobel Foundation through grants from the Tercentenary Foundation of the Bank of Sweden, by the Swedish Board for Space Activities, and the Royal Swedish Academy of Sciences, which is gratefully acknowledged. Appreciated contributions "in natura" were also received from the town of Kiruna and the LKAB Company.
Download or read book Magnetospheric Plasma Sources and Losses written by Bengt Hultqvist and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 491 pages. Available in PDF, EPUB and Kindle. Book excerpt: This sixth volume in the ISSI Space Sciences Series is a fully integrated book that gives an authoritative overview of all aspects of the topic in a well-organized form. Leading international scientists from all over the world contributed consistent, cross-referenced articles of high scientific standard.
Download or read book Solar Plasma Geomagnetism and Aurora written by Sydney Chapman and published by . This book was released on 1964 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiple Crossings of a Very Thin Plasma Sheet in the Earth s Magnetotail written by Donald H. Fairfield and published by . This book was released on 1981 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interactions of Earth s Magnetotail Plasma with the Surface Plasma and Magnetic Anomalies of the Moon written by Yuki Harada and published by Springer. This book was released on 2014-08-18 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the essential features of Moon-plasma interactions with a particular emphasis on the Earth's magnetotail plasma regime from both observational and theoretical standpoints. The Moon lacks a dense atmosphere as well as a strong intrinsic magnetic field. As a result, its interactions with the ambient plasma are drastically different from solar-wind interactions with magnetized planets such as Earth. The Moon encounters a wide range of plasma regime from the relatively dense, cold, supersonic solar-wind plasma to the low-density, hot, subsonic plasma in the geomagnetic tail. In this book, the author presents a series of new observations from recent lunar missions (i.e., Kaguya, ARTEMIS, and Chandrayaan-1), demonstrating the importance of the electron gyro-scale dynamics, plasma of lunar origin, and hot plasma interactions with lunar magnetic anomalies. The similarity and difference between the Moon-plasma interactions in the geomagnetic tail and those in the solar wind are discussed throughout the thesis. The basic knowledge presented in this book can be applied to plasma interactions with airless bodies throughout the solar system and beyond.
