The source of radiation from Jupiter at decimeter wavelengths

The flux of radiation from Jupiter at decimeter wavelengths is relatively large, and is approximately independent of wavelength in the interval from 3 cm to 68 cm. Four possible sources of this radiation are proposed and discussed quantitatively. It is concluded that the radiation does not originate in Jupiter's ionosphere, nor does it seem likely that it comes from its atmosphere. It is not due to synchrotron radiation by cosmic-ray electrons. On the other hand, electrons from the sun which are trapped in Jupiter's magnetic field may very well be the source. Observations for testing whether this possibility is correct are discussed.