The Solar Constant and Terrestrial Magnetism

Abstract

A LETTER in NATURE, November 28, p. 785, under the above title by Dr. G. C. Abbot, discusses a recent paper of mine in the Proceedings of the Royal Society. It refers to two of the subjects investigated in my paper, the 27–day interval, and the relation between corresponding daily values of S (the solar constant), as published by Dr. Abbot, and of C the international character figure, intended to supply a measure of magnetic disturbance. To take the second question first, Dr. Abbot's statement is as follows: “Dr. Chree does find indications of magnetic disturbance associated with low values of the solar constant. Inasmuch as higher solar constant values are generally associated with numerous sunspots and abundant magnetic disturbances, he thinks this paradoxical finding of low solar constants associated with magnetic disturbances is non significant. On the contrary, it is exactly what we should expect…the passage of an individual sunspot group over the central meridian of the solar disc is almost always associated with decreased values of the solar constant, and doubtless frequently with floor terrestrial magnetic disturbances. Hence it is prevailingly with low rather than high solar constant values that individual magnetic disturbances will be found associated.”