Coronal Expansion and Solar Wind

Little more than ten years have passed since spaceprobe-borne instruments con­ clusively demonstrated the existence of the solar wind. These observations con­ firmed the basic validity of a theoretical model, first proposed by E. N. Parker, predicting a continuous, rapid expansion of the solar corona. The subsequent decade has seen a tremendous growth in both the breadth and sophistication of solar wind observations; the properties of the interplanetary plasma near the orbit of the earth ar...