Reexamining the Correlation of Complex Solar Type III Radio Bursts and Solar Energetic Particle (SEP) Events

R.J. MacDowall1, I.G. Richardson2,3,4, R.A. Hess1,5, T. Golla1,4

1Code 695, NASA Goddard Space Flight Center, Greenbelt, MD 20771 USA
2Code 661, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
4Department of Astronomy, University of Maryland, College Park, MD 20742, USA
5Wyle Information Systems Group, McLean, VA 22102, USA

Interplanetary radio observations provide important information on particle acceleration processes at the Sun, and the propagation of the accelerated particles in the solar wind. Cane et al. [JGR, 2002] have drawn attention to a class of radio emissions that they find accompany 'essentially all' >20 MeV solar proton events. They call these bursts 'type III-L' because: they are fast drifting (like normal type III bursts associated with electrons accelerated at impulsive solar flares); they are Long-lasting compared to normal type III bursts; they occur Late compared to the onset of the related solar event; and, they commence at Lower frequencies (~100 MHz) than normal type III bursts, suggesting that they originate higher in the corona at <~0.5 Rs above the Sun. These complex bursts are typically the most prominent feature in radio emissions associated with SEPs. In this presentation, we report on an analysis of the complete Wind Waves and near-Earth SEP data sets for correlated radio and SEP events. We discuss the extent to which the characteristics of the complex type III bursts permit them to serve as proxies for SEP event occurrence and intensity.