SOME CHARACTERISTICS OF THE ELF VLF RADIO NOISE MEASURED NEAR LAQUILA, ITALY

New measurements are reported of radio noise by a Stanford University ELF/VLF radiometer located near L'Aquila, Italy, which at ELF/VLF freq uencies (10 Hz-32 kHz) can be considered a typical location for the Me diterranean area. The measurements, which were made primarily during 1 987, provide information on the average and root mean square (rms) amp litudes in 16 narrow frequency bands (5% bandwidth) distributed throug h the range of 10 Hz-32 kHz. Later processing of these data gives the V(d) statistic, which is a measure of the impulsiveness of the noise. The L'Aquila noise amplitudes tend to be higher during the summer than during the winter, particularly at the higher frequencies covered by the measurements, and the afternoon and evening amplitudes also tend t o be higher than those measured at other times during the day. The amp litudes decline with increasing frequency approximately as f-1, in agr eement with other observations around the world, whereas V(d) tends to increase with frequency, indicating increased impulsiveness at the hi gher frequencies.