Enhanced solar wind ³He2+ associated with coronal mass ejections
Abstract
Using data from the MASS high-resolution solar wind spectrometer on the WIND spacecraft, six enhanced ³He2+/4He2+ periods were identified from January 1995 to May 1998. The ratios observed in these events are four to ten times higher than previously reported average solar wind values. All enhanced ³He2+ periods were associated with the passage of CME-ejecta. The observed time periods were either within but towards the end of the CME-associated magnetic clouds or trailing the magnetic cloud by about 24 hours. All the enhanced ³He2+ periods have a mixture of low (cold) iron charge states along with high (hot) oxygen charge states. The unusual charge state composition of these enhanced ³He2+ events suggests the plasma came from a relatively cold and dense solar region, or from a rapidly expanding plasma parcel in the corona. We suggest that the enhanced ³He2+ plasma originated from the prominence core embedded within the CME.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- February 2000
- DOI:
- 10.1029/1999GL003660
- Bibcode:
- 2000GeoRL..27..309H
- Keywords:
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- Interplanetary Physics: Ejecta;
- driver gases;
- and magnetic clouds;
- Interplanetary Physics: Solar wind plasma;
- Space Plasma Physics: Ionization processes