Audio-Frequency Atmospherics

Various types of musical and nonmusical atmospherics occurring within the frequency range lying between 150 and 4000 cycles have been studied. Particular attention is directed to two types of the former, one a short damped oscillation, apparently a multiple reflection phenomenon, and the other a varying tone of comparatively long duration, probably related to magnetic disturbances. Several quasi musical atmospherics which appear to be associated with the two more distinct types are described. Dependence of atmospheric variations on diurnal, seasonal, and meteorological effects are discussed. Characteristics of audio-frequency atmospherics are shown in oscillograms and graphs.