XII. The waveforms of atmospherics and the propagation of very low frequency radio waves

Summary The responses of narrow-band receivers to individual radio atmospherics have been observed in order to describe the propagation of radio waves of frequency 2 kc./s. to 10 kc./s. over the surface of the earth. It has been found that the atmospherics from a fixed distance are sufficiently uniform to enable the relative attenuations of different frequencies to be deduced. The study reveals that waves of frequency below about 8 kc./s. are heavily attenuated during the daytime but are propagated freely at night. The attenuation is greater during a sudden ionospheric disturbance. These results confirm and extend those obtained recently by Gardner. They can be explained in outline on a theory recently proposed by Budden.