Jupiter's decametric radio emission and solar activity

The possibility of a short-term correlation between Jupiter's decametric radio emission and solar activity has been investigated for the 14 apparitions between 1960 and 1975. Artificial periodicities in the Jupiter data and other complicating factors are discussed, and it is found that the most serious periodicities liable to be present are Io-dependent. Using the geomagnetic Asub(p) index as the indicator of solar activity, the Chree superposed epoch technique is applied to the Non-Io events which seems to indicate a consistent picture of Non-Io related Jupiter emission being activated in some manner by solar wind particles, having radial velocities in the range 300-400 km s-1. It seems unlikely that this conclusion is due to artificial periodicities in the data. The most prominent of these latter, in the range of interest, also involve Io or can be accounted for. (U.K.)