U.S. National Report, 1967–1971: Fifteenth General Assembly, IUGG: Solar Activity as Relevant to Solar Planetary Relationships



A review of those aspects of solar activity relevant to solar planetary relationships is nearly impossible to construct. On the one hand there is the temptation to argue that all solar physics is ultimately related to understanding such relationships. A brief but comprehensive review of progress in solar physics in the last 4 years is clearly beyond the capability of a single author. On the other hand there is the danger that a single author's conception of what is relevant is most certainly distorted. Thus areas of important progress may be slighted or totally ignored. The present review is generally restrictive rather than inclusive. It is organized to discuss the most outstanding developments in the areas of the general activity cycle, active regions, the role of magnetic fields, transient events, and solar-geomagnetic relations.