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SPRG Seminars - Archive
April 4, 2006:
Solar Energetic Electron Events observed by WIND/3DP
Linghua Wang, UC Berkeley / Space Sciences Laboratory
Electron/3He-rich SEP events (impulsive SEP events) are the most common solar particle events, but they exhibit high charge states and unusual enhancements of 3He and heavy nuclei. In the presented study, we focused on those events. First, in the case study we selected 9 good scatter-free impulsive electron events to ignore scattering in the interplanetary medium. Then we obtained electron injection profiles at the Sun from triangular fitting to in situ observations at 1 AU. We found two different electron injections. Second, we selected 11 impulsive SEP events with both good electron and ion observations and compared the timing between electrons and 3He-rich ions. We found the delayed ion injection after electrons at the Sun. Finally, in the statistical study we presented the time variation of solar electron events over one solar cycle. After correcting for the high instrumental background, we found a power-law relationship between the event number N and the electron peak flux J: dN/dJ = A*J^(-gamma). It suggests that ~104 events/year occur over the whole Sun near solar maximum.