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Description
We survey the statistical properties of 1191 solar electron events observed by the WIND 3DP instrument from <1keV to >~300keV for a solar cycle (1995 through 2005). After taking into account times of high background, the corrected occurrence frequency of solar electron events versus peak flux exhibits a power-law distribution over three orders of magnitude with exponents between -1.0 and -1.6 for different years, comparable to the frequency distribution of solar proton events, microflares, and coronal mass ejections (CMEs), but significantly flatter than that of soft X-ray (SXR) flares. At 40keV (2.8keV), the integrated occurrence rate above ~0.29 (~330)/cm2/s.sr^-1^/keV near 1 AU is ~1000/year (~600/year) at solar maximum and ~35/year (~25/year) at solar minimum, about an order of magnitude larger than the observed occurrence rate. We find these events typically extend over ~45{deg} in longitude, implying the occurrence rate over the whole Sun is ~10^4^/year near solar maximum. The observed solar electron events have a 98.75% association with type III radio bursts, suggesting all type III bursts may be associated with a solar electron event. They have a close (~76%) association with the presence of low-energy (~0.02-2MeV/nucleon), ^3^He-rich (^3^He/^4^He>=0.01) ion emissions measured by the ACE ULEIS instrument. For these electron events, only ~35% are associated with a reported GOES SXR flare, but ~60% appear to be associated with a CME, with ~50% of these CMEs being narrow. These electrons are often detected down to below 1keV, indicating a source high in the corona.
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