Short-Term Correlations of Decameter Radio Emission from Jupiter and Solar Activity.

Abstract

view Abstract Citations (1) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Short-Term Correlations of Decameter Radio Emission from Jupiter and Solar Activity. Sastry, Ch. V. Abstract An analysis of decameter radio emission from Jupiter and solar activity over the past 10 yr by the Chree method of superposed epochs showed that there is a significant increase in the radio emission from Jupiter following enhanced solar activity during the past sunspot maximum. The indices used to represent solar activity are (1) geomagnetic planetary index Ap, (2) solar radio flux at centimeter wavelengths. It is pointed out that due to the directivity of the source on Jupiter, the effect of the satellite lo and the observing procedures the Jupiter data contain periodicities which are not inherent in the source. These periodicities are estimated in the following way. A two-dimensional histogram giving the occurrence probability as a function of LCM (system III) and the position of the satellite lo is calculated using all the available data. For an assumed 4 h observing function each day the theoretical probability of ohserving Jupiter based on the two-dimensional histogram is calculated for a number of days. A power spectrum analysis of these theoretical probabilities showed that there can be a number of periodicities in Jupiter data with periods ranging from 2 to 30 days. It is well known that solar data exhibit similar periodicities. The observed correlations may be due to the existence of similar periodicities in both time series. To test this hypothesis the probability of observing Jupiter for each day, for which observing times are available, during the period 1957 through 1961 is calculated using the two-dimensional histogram. These theoretical probabilities are correlated with the solar indices for the same period. The correlation curves thus obtained are similar to the correlation curves obtained by using the days on which Jupiter emission is detected. On the basis of these results it is suggested that there is no conclusive evidence that decameter radio emission from Jupiter and solar activity are related. Publication: The Astronomical Journal Pub Date: February 1966 DOI: 10.1086/110086 Bibcode: 1966AJ.....71R.179S full text sources ADS |