RESEARCH ON VLF PROPAGATION IN ARCTIC REGIONS. GEOPHYSICAL EFFECTS

• Main Author: WHITSON,ARTHUR L.
• Other Authors: STANFORD RESEARCH INST MENLO PARK CALIF
• Format: Text
• Language: English
• Published: 1961
• Subjects: *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; Arctic; Fairbanks
• Online Access: http://www.dtic.mil/docs/citations/AD0256062; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0256062

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)