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Polar-cap and auroral-zone absorption effects on 2.5- and 5.0-megacycles per second atmospheric radio noise

1962; American Geophysical Union; Volume: 67; Issue: 6 Linguagem: Inglês

10.1029/jz067i006p02299

2156-2202

John R. Herman,

Geomagnetism and Paleomagnetism Studies

Atmospheric radio noise data on 2.5 and 5.0 Mc/s at Enkoping, Sweden, and Thule, Greenland, have been analyzed for 10 polar-cap and auroral-zone absorption events occurring in the years 1958–1960. Results show that the measured noise power is radically depressed during such events. At Enkoping, ‘maximum decrease’ on 2.5 and 5.0 Mc/s ranged from 10 to 36 db and from 6 to 38 db below normal, respectively. The corresponding ranges at Thule were 5 to 24 and 6 to 14 db below normal. Noise amplitude distribution curves are similar in shape for both ionospherically quiet and disturbed periods; on the average, the disturbed-period envelope is about 7 db below normal.