Geomagnetic Micropulsations

Geomagnetic Micropulsations PDF

Author: J. A. Jacobs

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 187

ISBN-13: 3642868282

DOWNLOAD EBOOK →

The subject of geomagnetic micropulsations has developed extremely rapidly and it is difficult to know when is an appropriate time to pause and assess the sum total of our knowledge-both observational and theoretical. There has in recent years been a tremendous increase in both the quantity and quality of data and also many theoretical ad vances in our understanding of the phenomenon. Undoubtedly there will be further progress in both areas but it seems worthwhile now to review both our knowledge and our ignorance. This book was essen tially completed by the end of April 1969 and tries to give a summary of the subject up to that time. The Earth is enclosed in the magnetosphere, a hollow carved out of the solar wind by the Earth's magnetic field. Above the ionosphere there is a very tenuous thermal plasma of partially ionized hydrogen in diffusive equilibrium with magnetic and gravitational forces, and ener getic protons and electrons that constitute the trapped Van Allen ra diation belts. Throughout this anisotropic and inhomogeneous plasma, natural and man-made electromagnetic energy propagates in a wide variety of modes and frequency bands. This book is concerned with that class of natural signals called geomagnetic micropulsations-short period (usually of the order of seconds or minutes) fluctuations of the Earth's magnetic field.

Generation of Artificial Geomagnetic Micropulsations with a Large Ground Based Current Loop

Generation of Artificial Geomagnetic Micropulsations with a Large Ground Based Current Loop PDF

Author: Stanford University. Stanford Electronics Laboratories

Publisher:

Published: 1972

Total Pages: 124

ISBN-13:

DOWNLOAD EBOOK →

The purpose of this study is to investigate and, if possible, establish the feasibility of producing artificial geomagnetic micropulsations by using a large horizontal current loop on the ground. Most natural micropulsations appear to be produced by hydromagnetic (hm) waves propagating in the ionosphere and/or the magnetosphere, and the term 'artificial micropulsations' is used to mean artificially produced hm waves with propagation characteristics similar to those of the natural signals. The critical quantity in the generation process for the hm waves is to the amplitude of the magnetic field variation that can be produced in the ionospheric E-region by the ground-based loop. Currents are induced in the conducting earth beneath the loop whenever its current is varied, and these currents have a magnetic field opposing the magnetic field of the loop. If either the conductivity of the earth or the variation frequency is too high the field at E-region heights may be reduced to a level where negligible hm wave amplitudes are produced. The effect of these earth currents is calculated for an assumed single-layer earth and for a wide range of frequencies and earth conductivities. (Author).

ULF Pulsations in the Magnetosphere

ULF Pulsations in the Magnetosphere PDF

Author: D.J. Southwood

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 154

ISBN-13: 940098426X

DOWNLOAD EBOOK →

Physical and chemical studies of the earth and planets along with their sur roundings are now developing very rapidly. As these studies are of essentially international character, many international conferences, symposia, seminars and workshops are held every year. To publish proceedings of these meetings is of course important for tracing development of various disciplines of earth and plane tary sciences though publishing is getting fast to be an expensive business. It is my pleasure to learn that the Center for Academic Publications Japan and the Japan Scientific Societies Press have agreed to undertake the publication of a series "Advances in Earth and Planetary Sciences" which should certainly become an important medium for conveying achievements of various meetings to the aca demic as well as non-academic scientific communities. It is planned to publish the series mostly on the basis of proceedings that appear in the Journal of Geomagnetism and Geoelectricity edited by the Society of Terrestrial Magnetism and Electricity of Japan, the Journal of Physics of the Earth by the Seismological Society of Japan and the Volcanological Society of Japan, and the Geochemical Journal by the Geochemical Society of Japan, . although occasional volumes of the series will include independent proceedings. Selection of meetings, of which the proceedings will be included in the series, will be made by the Editorial Committee for which I have the honour to work as the General Editor.

Lanterna Rally - Theme by Grace Themes