L-bursts in Jupiter's decametric radio spectra

Dynamic spectra of Jupiter's L-bursts are observed with high-resolution radio spectrographs. The L-bursts are characterized by their emission envelopes. The duration of envelopes varies from one to a few seconds increasing towards the opposition of Jupiter to reach a maximum in the vicinity of 10 to 20 d after opposition. Modulation lanes appear within the emission envelopes. The magnitude of thef-t slopes of lanes is determined by the central meridian longitude (CML) of Jupiter, and partly by the longitude of Io. The sign of the slopes depends on the CML only. The yearly averages for thef-t slopes do not seem to be related to the Jovicentric declination of the Earth. Most lanes are relatively faint. A summary of the properties of modulation lanes is given. A peculiar case of polarization of an L-burst is shown. Certain shadow events are interpreted as occultation effects caused by overdense meteor trails drifting in the upper atmosphere winds.