Kilometric Continuum Radiation

James L. Green, Scott Boardsen


Kilometric continuum (KC) is the high frequency component (~100 kHZ to ~800 kHz)
of Non-thermal continuum (NTC).  Unlike escaping NTC (~30 kHz to ~100 kHz) whose
source is around the dawn sector, the source of KC occurs at all Magnetic local
times. The latitudinal beaming of KC as observed by Geotail is, for most events,
restricted to +/- 15o magnetic latitude. KC has been observed during periods of
both low and strong geomagnetic activity, with no significant correlation of
wave intensity with Kp index. However statistically the maximum observed
frequency of KC emission tends to increase with Kp index, the effect is more
pronounced around solar maximum, but is also detected near solar minimum.  There
is strong evidence that the source region of KC is from the equatorial
plasmapause during periods when a portion of the plasmapause moves inwards from
its nominal position. Case studies have shown the KC emissions seem to be
associated with plasmaspheric notches, shoulders and tails. There is a recent a
focus on trying  to understand the banded frequency structure of this emission
and its relationship to plasmaspheric density ducts and irregularities in the
source region.

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Submitted to Radio Science Bulletin, 2005