Ionospheric Disturbance at the Time of Cosmic Ray Increases

IN a recent communication Legrand and Helary1 have reported the occurrence of an anomalous increase in the intensity of the total cosmic ray component at the Paris Cosmic Ray Survey Station on December 4, 1957. At about the same time an increase was also observed in the intensity of the nucleonic component at Thule, Greenland. This cosmic ray event was further described as being analogous to one which was observed at Paris on January 21, 1957 (ref. 2). It has been suggested that these events are manifestations of the precipitation into the Earth's atmosphere of high-energy protons which emanate from the disturbed Sun.