Advances in magnetospheric physics: Aurora

To write a brief review of progress in auroral physics of the last quadrennium 1971–1974 is akin to fitting 27 students in a Volkswagen—it can be done ( Guiness Book of Records ), but no one will be quite satisfied with the space he has. Auroral physics has not been spared from the science information explosion of recent years, and I make no claim to having read all relevant papers nor even being aware of the more significant advances in all of the various subsections of the field. Consequently, the writing of this review was preceded by a polling of auroral scientists for a short summary of their significant work over the last 4 years—to those few workers I may have inadvertently missed, I apologize; to those few workers who responded, I thank. It seems inevitable that some personal bias will enter a review of this nature but I hope that it is minimal. The approach adopted assumes a reader with a professional working knowledge of auroral physics as it was understood at the end of 1970.