High-frequency and time resolution rocket observations of structured low- and medium-frequency whistler mode emissions in the auroral ionosphere

Citation
J. Labelle et al., High-frequency and time resolution rocket observations of structured low- and medium-frequency whistler mode emissions in the auroral ionosphere, J GEO R-S P, 104(A12), 1999, pp. 28101-28107
Citations number
25
Categorie Soggetti
Space Sciences
Journal title
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
ISSN journal
21699380 → ACNP
Volume
104
Issue
A12
Year of publication
1999
Pages
28101 - 28107
Database
ISI
SICI code
0148-0227(199912)104:A12<28101:HATRRO>2.0.ZU;2-U
Abstract
High bandwidth electric field waveform measurements on a recent auroral sou nding rocket reveal structured whistler mode signals at 400-800 kHz. These are observed intermittently between 300 and 500 km with spectral densities 0-10 dB above the detection threshold of 1.5 x 10(-11) V-2/m(2) Hz. The lac k of correlation with local particle measurements suggests a remote source. The Signals are composed of discrete structures, in one case having bandwi dths of about 10 kHz and exhibiting rapid frequency variations of the order of 200 kHz per 100 ms. In one case, emissions near the harmonic of the whi stler mode signals are detected simultaneously. Current theories of auroral zone whistler mode emissions have not been applied to explain quantitative ly the fine structure of these signals, which resemble auroral kilometric r adiation (AKR) rather than auroral hiss.