Bøger af Y. Kamide

As a star, the sun is continuously emitting an enormous amount of energy 33 into space, up to as much as 3. 9 X 10 erg/ s. This energy emission consists of three modes. Almost all the energy is emitted in the form of the familiar black-body radiation, commonly called sunlight. Although the amount of energy emitted is small, the sun also emits x rays, extreme ultraviolet (EUV), and UV radiations, which are absorbed above the earth's stratosphere. These constitute the second mode of solar energy, separate from the black-body radiation that penetrates the lower layers of the atmosphere. The sun has another important mode of energy emission in which the energy is carried out by charged particles. These particles have a very wide range of energies, from less than I keY to more than I GeV. Because of this wide range, it is convenient to group them into two components: particles with energies greater than 10 keY and the lower-energy particles. The former are generally referred to as solar protons or solar cosmic rays; their emission is associated with active features on the sun. Their interaction with the atmosphere is similar to that of the x ray and EUV radiation. Low-energy particles constitute plasma, a gas of equal numbers of positive and negative particles. Actually, this plasma is the outermost part of the solar atmosphere, namely the corona, which blows out continuously . For this reason, the plasma flow is called the solar wind.

This monograph is the outgrowth of an AGU (American Geophysical Union) Chapman Conference on Solar Wind-Magnetosphere Coupling, and it contains most of the formal papers presented at the conference including the summary panel. The conference was held on February 12-15,1985 at the Jet Propulsion Laboratory of the California Institute of Technology in Pasadena, California, U.S.A. It was attended by over 150 scientists from most of the nations active in space research. The purpose of the conference was to bring together scientists from all areas of solar-terrestrial physics, both theoretical and experimental, in order to focus attention on the solar wind-magnetosphere coupling problem, to provide a timely forum for the exchange of ideas, and to promote interdisciplinary collaboration. The conference agenda consisted of eight sessions: six topical, one poster, and one summary. The topical sessions were "Solar Wind and Geomagnetic Activity," "AM PTE Mission," "Solar Wind and Polar Cusp," "Auroral Zone and Polar Cap," "Solar Wind and Magnetotail," and "Theoretical Modeling and Simulations." The conference concluded with a two-hour summary panel discussion which attempted to provide an assessment of the progress that has been made as well as underscore the problems, old and new, which remain unanswered. Sydney Chapman (1889-1970) was one of the early pioneers in the study of the influence of the sun and magnetosphere on the earth's upper atmosphere, and it was most appropriate that this conference be one in the AGU series named in his honor.

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.