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Low-frequency noise observed in the distant magnetosphere with OGO 1

1970; American Geophysical Union; Volume: 75; Issue: 10 Linguagem: Inglês

10.1029/ja075i010p01854

2156-2202

N. Dunckel, B. P. Ficklin, L. H. Rorden, R. A. Helliwell,

Seismic Waves and Analysis

Journal of Geophysical Research (1896-1977)Volume 75, Issue 10 p. 1854-1862 Low-frequency noise observed in the distant magnetosphere with OGO 1 N. Dunckel, N. DunckelSearch for more papers by this authorB. Ficklin, B. FicklinSearch for more papers by this authorL. Rorden, L. RordenSearch for more papers by this authorR. A. Helliwell, R. A. HelliwellSearch for more papers by this author N. Dunckel, N. DunckelSearch for more papers by this authorB. Ficklin, B. FicklinSearch for more papers by this authorL. Rorden, L. RordenSearch for more papers by this authorR. A. Helliwell, R. A. HelliwellSearch for more papers by this author First published: 1 April 1970 https://doi.org/10.1029/JA075i010p01854Citations: 77AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Abstract Two new types of low-frequency noise, designated 'broadband' and 'highpass' have been detected in the distant magnetosphere by the VLF/LF experiment on the OGO 1 satellite. Broadband noise extends over the entire range of observations from 0.2 to 100 kHz and the intensity decreases with increasing frequency. It occurs in bursts having durations of a few minutes or less. It shows no connection with any of the expected plasma cutoff or resonance frequencies and is believed to be a nonpropagating disturbance generated in the vicinity of the satellite. Highpass noise extends from a characteristic low-frequency cutoff to above 100 kHz and occurs in bursts lasting tens of minutes. This cutoff has only been observed above 20 kHz. Above the cutoff the intensity shows little variation with frequency. Both types of noise are observed predominantly at L greater than 5 in or near the night hemisphere. The occurrence of both types of noise is highly correlated with the auroral electrojet index. Several times noise bursts began within 2 min of the onset of micropulsations in the polar region even though the satellite was near apogee (24 earth radii). The peak rms magnetic intensity in a highpass noise burst has a maximum of 8×10−5 γ Hz1/2 and averages 10−5 γ Hz−1/2. 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