Bücher von Syun-Ichi Akasofu

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 book describes the history of the progress made in auroral science and magnetospheric physics by providing examples of ideas, controversies, struggles, acceptance, and success in some instances. The author, a distinguished auroral scientist, fully describes his experiences in characterizing and explaining auroral phenomena.

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. 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.

Prominent progress in science is inevitably associated with controversies. This book, which is based on my own experiences as a scientist, describes the history of the progress made in auroral science and magnetospheric physics by providing examples of ideas, controversies, struggles, acceptance, and success in some instances.