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Solar Cycle Dependence of the Quiet-time Composition of Suprathermal Ions Tuesday Aug 1 SHINE 2006. Mihir I. Desai Southwest Research Institute San Antonio, Texas Co-authors: Glenn M. Mason, Joseph E. Mazur & Joseph R. Dwyer. 486. CME shocks.
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Solar Cycle Dependence of the Quiet-time Composition of Suprathermal Ions Tuesday Aug 1 SHINE 2006 Mihir I. Desai Southwest Research Institute San Antonio, Texas Co-authors: Glenn M. Mason, Joseph E. Mazur & Joseph R. Dwyer
486 CME shocks Must encounter 3He- and heavy ion-rich flare material in the corona and the IP medium
3He during quiet-times (Wiedenbeck et al. 2003 SW10).
Injection Energy above bulk solar wind speed Seed population for large SEP events • Heated solar wind ions • Interstellar & inner source pick-up ions • Ions accelerated in prior solar and interplanetary activity (Mewaldt et al., 2001 AIP conference Proceedings 598, 165)
Summary C/O and Fe/O ratios are similar to solar wind and CIR values during solar minimum conditions of 1994-1997 and 2005. During periods of increased solar activity between 1998-2002, the C/O ratio is similar to that measured in SEP events, while the Fe/O ratio lies in between the values measured in CME-driven IP Shock and SEP events. The 3He/4He ratio lies in the 1.5-5% range during August 1997–2005, but it dropped by an order of magnitude during 2005.
Conclusions Composition of suprathermal ions above ~6 times the solar wind speed is dynamic and is essentially dominated by ions accelerated in SEP events during solar maximum conditions of 1998-2004 and by suprathermal solar wind/CIR ions during solar minimum periods of 1994-1997 and 2005.