Accession Number : AD0256062

Title :   RESEARCH ON VLF PROPAGATION IN ARCTIC REGIONS. GEOPHYSICAL EFFECTS

Corporate Author : STANFORD RESEARCH INST MENLO PARK CALIF

Personal Author(s) : WHITSON,ARTHUR L.

Report Date : FEB 1961

Pagination or Media Count : 1

Abstract : Atmospheric noise data collected in the Arctic were used to determine certain geophysical effects on VLF propagation between 3 and 30 kc in arctic regions. The effect of sudden ionospheric disturbances in the form of a sudden enhancement of atmospherics is defined in the 3 to 30 kc frequency band. Very-low-frequency propagation along the Fairbanks-Thule great-circle path,AS MEASURED BY Fourier analysis of atmospherics, is non-reciprocal but disagrees with non-reciprocal measurements at mid-latitudes. The influence of a polar-cap-absorption event on atmospheric noise is shown, along with variations in atmospheric noise spectrum that are related to some unexplained VLF propagation phenomena. (Author)

Descriptors :   *PROPAGATION, *RADIO WAVES, ATMOSPHERICS, EXTRATERRESTRIAL RADIO WAVES, EXTREMELY LOW FREQUENCY, GEOPHYSICS, IONOSPHERIC DISTURBANCES, IONOSPHERIC PROPAGATION, MEASUREMENT, NOISE ANALYZERS, POLAR REGIONS, SOLAR DISTURBANCES, SOLAR FLARES, VERY LOW FREQUENCY

Distribution Statement : APPROVED FOR PUBLIC RELEASE