Correlation studies between solar wind parameters and the decimetric radio emission from Jupiter

Results of a study comparing long-term time variations (years) in Jupiter's synchrotron radio emission with a variety of solar wind parameters and the 10.7-cm solar flux are reported. Data from 1963 through 1985 were analyzed, and the results suggest that many solar wind parameters are correlated with the intensity of the synchrotron emission produced by the relativistic electrons in the Jovian Van Allen radiation belts. Significant nonzero correlation coefficients appear to be associated with solar wind ion density, ram pressure, thermal pressure, flow velocity, momentum, and ion temperature. The highest correlation coefficients are obtained for solar wind ram pressure (NV/sup 2/) and thermal pressure (NT). The correlation analysis suggests that the delay time between fluctuations in the solar wind and changes in the Jovian synchrotron emission is typically about 2 years. The delay time of the correlation places important constraints on the theoretical models describing the radiation belts. The implication of these results, if the correlations are real, is that the solar wind is influencing the supply and/or loss of electrons to Jupiter's inner magnetosphere. We note that the data for this work spans only about two periods of the solar activity cycle, and because of the long time scalesmore » of the observed variations, it is important to confirm these results with additional observations. copyright American Geophysical Union 1989« less

[1]  G. Ioannidis,et al.  The magnetospheres of Jupiter and Earth , 1970 .

[2]  M. Desch,et al.  Phenomenology of magnetospheric radio emissions , 1983 .

[3]  N. Brice.  Energetic protons in Jupiter's radiation belts , 1972 .

[4]  S. Gulkis,et al.  The Magnetosphere of Jupiter , 1969 .

[5]  É. Gérard.  Long-Term Variations of the Decimeter Radiation of Jupiter , 1970 .

[6]  M. Neugebauer.  The quiet solar wind , 1976 .

[7]  J. Feynman.  Solar Cycle and Long Term Changes in the Solar Wind , 1983 .

[8]  É. Gérard.  Long Term Variations of the Decimetric Radio Emission of Jupiter (and Saturn , 1975 .

[9]  M. Kivelson,et al.  Physics of the Jovian Magnetosphere , 1983 .

[10]  J. King.  Interplanetary medium data book , 1977 .

[11]  J. Roberts,et al.  Observations of Jupiter's radio spectrum and polarization in the range from 6 cm to 100 cm , 1965 .

[12]  J. King,et al.  Interplanetary medium data book. Supplement 3: 1977-1985 , 1986 .

[13]  M. Neugebauer.  Measurements of the properties of solar wind plasma relevant to studies of its coronal sources , 1982 .

[14]  F. Shimabukuro.  The Solar Spectrum Above 1 mm , 1977 .

[15]  A. Jursa,et al.  Handbook of geophysics and the space environment , 1985 .

[16]  W. Feldman,et al.  Plasma and Magnetic Fields from the Sun , 1977 .

[17]  M. Klein.  The variability of the total flux density and polarization of Jupiter's decimetric radio emission , 1976 .

[18]  B. Burke,et al.  Observations of a variable radio source associated with the planet Jupiter , 1955 .