The Magnetic Disturbance of March 24–25

Abstract

A CONSIDERABLE magnetic disturbance occurred on March 24–25, as recorded by the Stonyhurst magnetographs. There was no marked sudden commencement of the disturbance, but the declination magnet began to move steadily towards the W., accompanied by a decrease in horizontal force, between the hours 8 and 9 G.M.T. The declination magnet attained the extreme limit of its westerly movement at 13 h. 14 m., when it began to move gradually towards the E. At 17 h. 12 m. a period of rapid oscillations commenced on the declination magnet. On the horizontal force magnet the decrease in force was succeeded, at 12 h. 24 m., by an o increase. A very rapid oscillation of increase and decrease occurred between 17 h. 2 m. and 17 h. 18 m., the range being 88 (1 10⁵ C.G.S. unit).