Frequency modes in the interplanetary medium:
Evidence for a non-random interplanetary medium and a solar source
D. J. Thomson, L. J. Lanzerotti, and C. G. Maclennan
Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974 USA
Several years ago it was reported that a detailed time series analysis of particle flux data from the Ulysses spacecraft,
as well as a number of data sets from other spacecraft, showed conclusive evidence for distinct modal structures in
the fluxes (Thomson, Maclennan, and Lanzerotti, Nature, 376, 139, 1995). It was furthermore concluded that the numerous
identified frequencies could be identified with known solar p-mode frequencies and with several calculated solar g-mode
frequencies. This report was challenged by several groups, both on the basis of the thought-to-be well understood nature
of the interplanetary medium (largely characterized as a random medium) and the solar driving source. In this paper we
present a summary of our past analyses, further analyses on the time variations of interplanetary particle fluxes made
simultaneously at the ACE and Ulysses spacecraft, and time series analysis of interplanetary magnetic field data from the
Ulysses spacecraft. We demonstrate that our previous conclusions are correct. Furthermore, we demonstrate that,
statistically, the fluctuations with time of the interplanetary magnetic field as measured by Ulysses instrumentation
are not totally random, but have a 40% to 60% deterministic modal structure.