THE SEARCH FOR SOLAR GRAVITY-MODE OSCILLATIONS IN THE SOLAR-WIND USING ULYSSES PLASMA DATA

A recent report that energetic particles measured in the solar wind ma y be influenced by solar gravity-mode (g-mode) oscillations motivated the search for g-mode signatures in the Ulysses solar wind plasma data . Ulysses solar wind plasma data from 1 March 1992 through the 12 Apri l 1996 were examined in this study for signs of possible solar oscilla tions. The multi-taper method for spectral analysis was used to look f or significant spectral peaks in the entire four-year data set, as wel l as in the smaller, more heliographically homogenous data set over th e solar poles. Several frequencies satisfying certain significance req uirements were found in the g-mode frequency range in both data sets t hat also agree with the previously published findings. However, these identifications are shown to be false detections, and hence the freque ncies found cannot be identified as solar g modes.