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Auroral hiss and kilometric radiation measured from the Viking satellite
Author(s) -
Bahnsen Axel,
Jespersen Mogens,
Ungstrup Eigil,
Iversen Iver B.
Publication year - 1987
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl014i004p00471
Subject(s) - hiss , physics , cyclotron , ionosphere , van allen radiation belt , radiation , astrophysics , geophysics , satellite , electromagnetic radiation , magnetosphere , plasma , computational physics , astronomy , optics , electron , nuclear physics
An extensive data base on high latitude waves will result from the ten month's operating period of the Viking satellite, during which the high frequency wave experiment, V4H, has worked continuously. Preliminary analysis of a small fraction of these data has given results concerning auroral kilometric radiation (AKR) as well as lower frequency waves. Our findings are: (1) AKR waves exist in both R‐X and L‐O mode, R‐X mode being strongest, (2) the frequency range of AKR is from about 100 kHz to at least 500 kHz, (3) the R‐X mode propagates upwards in a cone or conical shell filling less than a half sphere, (4) AKR is generated in a narrow latitudinal range within the auroral oval, in the evening sector, and at altitudes of several thousand kilometers, (5) AKR is electromagnetic at the source, no strong electrostatic mode is observed, (6) there is fine structure in AKR, as well as a continuous spectrum, (7) below the cyclotron frequency, auroral hiss, limited upwards by the plasma frequency, as well as Z mode radiation has been observed, (8) in the polar cap, electrostatic bursts of a few seconds duration are frequently observed.