Source and propagation characteristics of kilometric continuum observed with multiple satellites

摘要

Kilometric continuum radiation is the high-frequency extension of escaping continuum emissions in the frequency range from 100 to 800 kHz. It was first identified with the Geotail Plasma Wave Instrument (PWI) and has been observed with various satellites. Previous results from the IMAGE Radio Plasma Imager and extreme ultraviolet experiments show that kilometric continuum is generated at the plasmapause, in or near the magnetic equator, within a notch region. In this study, data from the CRRES PWI have also identified other new sources of kilometric continuum from equatorial density irregularities inside the plasmasphere as well as at the plasmapause. An example of CRRES observations reveals that kilometric continuum can be radiated into a wide-beam emission contrary to the beaming theory. IMAGE and Geotail simultaneous kilometric continuum observations measure a very broad emission cone of up to about ±30°.