Substorms 4

The Fourth International Conference on Substorms (ICS-4) was held at Lake Hamana, Japan on March 9-13, 1998. This volume represents a snapshot of substorm research as of 1998. The proceedings address the following key questions: What are the major expansion phase activities seen in various regions? What triggers the substorm expansion onset? What are the roles of waves and microscopic processes in large-scale substorm processes? What is the relationship between global convection and substorms? What is the role of the inner magnetosphere during substorms? For each of the five key questions, the current status of observational and modeling efforts in the field is presented in the invited and contributed papers. This volume will foster communication between magnetospheric and high-latitude ionospheric physicists and those scientists who are working primarily in the area of the thermosphere and low-latitude ionosphere.

It has become increasingly clear that the magnetosphere becomes intermittently unstable and explosively releases a large amount of energy into the polar upper atmos phere. This particular magnetospheric phenomenon is called the magnetospheric sub storm. It is manifested as an activity or disturbance ofvarious polar upper atmospheric phenomena, such as intense auroral displays and X-ray bursts. Highly active conditions in the polar upper atmosphere result from a successive occurrence of such an element ary activity, the polar substorm, which lasts typically of order one to three hours. The concept of the magnetospheric substorm and its manifestation in the polar upper atmosphere, the polar substorm, has rapidly crystallized during the last few years. We can find a hint of such a concept in the term 'polar elementary storm' introduced by Kristian Birkeland as early as 1908. However, we are greatly indebted to Sydney Chapman, who established the basic foundation of magnetospheric physics and has led researches in this field during the last half century. Indeed, the terms 'polar magnetic substorm' and 'auroral substorm' were first suggested by Sydney Chapman. The concept of the substorm was then soon extended by Neil M. Brice of Cornell University, and Kinsey A. Anderson and his colleagues at the University ofCaliforrlia, Berkeley, who introduced the term 'magnetospheric substorm'. We owe many of these recent developments in magnetospheric physics to the great international enterprise, the International Geophysical Year (IGY) and subse quent international cooperative effort (IGC, IQSY).

Man, through intensive observations of natural phenomena, has learned about some of the basic principles which govern nature. The aurora is one of the most fascinating of these natural phenomena, and by studying it, man has just begun to comprehend auroral phenomena in terms of basic cosmic electrodynamic processes. The systematic and extensive observation of the aurora during and after the great international enterprise, the International Geophysical Year (lGY), led to the concept of the auroral substorm. Like many other geophysical phenomena, auroral displays have a dual time (universal- and local-time) dependence when seen by a ground-based observer. Thus, it was a difficult task for single observers, rotating with the Earth once a day, to grasp a transient feature of a large-scale auroral display. Such a complexity is inevitable in studying many geophysical features, in particular the polar upper atmospheric phenomena. However, it was found that their complexity began to unfold when the concept of the auroral substorm was introduced. In a book entitled Polar and Magnetospheric Substorms, the predeces sor to this book, I tried to describe the auroral phenomena as completely as possible in terms of the concept of the auroral substorm. At that time, the first satellite observations of particles and magnetic fields during substorms were just becoming available, and it was suggested that the auroral sub storm is a manifestation of a magnetospheric phenomenon called the magnetospheric substorm.

Convection and substorms are magnetospheric phenomena used as paradigms for the study of the magnetosphere. This book presents a synthesis of the literature on convection and substorms, an analysis of their interactions, and proposes a model for reconnection. It will be useful for all scientists working in solar-terrestrial physics.

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.

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.

Jesuits established a large number of astronomical, geophysical and meteorological observatories during the 17th and 18th centuries and again during the 19th and 20th centuries throughout the world. The history of these observatories has never been published in a complete form. Many early European astronomical observatories were established in Jesuit colleges. During the 17th and 18th centuries Jesuits were the first western scientists to enter into contact with China and India. It was through them that western astronomy was first introduced in these countries. They made early astronomical observations in India and China and they directed for 150 years the Imperial Observatory of Beijing. In the 19th and 20th centuries a new set of observatories were established. Besides astronomy these now included meteorology and geophysics. Jesuits established some of the earliest observatories in Africa, South America and the Far East. Jesuit observatories constitute an often forgotten chapter of the history of these sciences.

Recombination lines at radio wavelengths have been - and still are - a pow erful tool for modern astronomy. For more than thirty years they have allowed astronomers to probe the gases from which stars form. They have even been detected in the Sun. In addition, observations of these spectral lines facilitate basic research into the atom, in forms and environments that can only exist in the huge dimensions and extreme conditions of cosmic laboratories. We intend this book to serve as a tourist's guide to the world of Radio Recombination Lines. It contains three divisions: a history of their discovery, the physics of how they form and how their voyage to us influences their spectral profiles, and a description of their many astronomical contributions to date. The appendix includes supplementary calculations that may be useful to some astronomers. This material also includes tables of line frequencies from 12 MHz to 30THz (AlOJLm) as well as FORTRAN computer code to calculate the fine structure components of the lines, to evaluate radial matrix integrals, and to calculate the departure coefficients of hydrogen in a cosmic environment. It also describes how to convert observational to astrophysical units. The text includes extensive references to the literature to assist readers who want more details.

Proceedings of the second Hellenic Cosmology Meeting, held in the National Observatory of Athens (Penteli, 19-20 April 2001)