Paper presented at AGU Spring Meeting, 26-29 May 1998, San Fransico, CA, USA
Using solar wind particle data from the CELIAS/MTOF sensor on the SOHO mission, we studied the abundance of the elements O, Ne, Mg, Si, S, Ca, and Fe for the time period around the January 6, 1997, coronal mass ejection event (CME). In the interstream and coronal hole regions before and after this event we found elemental abundance ratios consistent with the expected abundance patterns of the respective flow regimes. However, during the passage of the CME and during the passage of the erupted filament, which followed the CME, we found that the elemental composition differed markedly from the interstream and coronal hole regions before and after this event. During the passage of the CME and the passage of the erupted filament we found a mass-dependent element fractionation, with a monotonic increase of abundances toward heavier elements. We observed Si/O and Fe/O abundance ratios of about one half during these time periods, which is significantly higher than for interstream solar wind. We make an attempt to explain the observed abundace pattern in terms of M/Q dependent fractionation similar to the pattern found in SEP events.