The Analysis of Solar Energetic Particles

Fast–drift bursts (type III) can be used to trace field lines from theSun into the interplanetary medium. Emission above 100 MHzoriginates within 0.5 solar radii of the photosphere whereasemission at 10 MHz originates at about 2 solar radii. If the burstsextend to the lowest frequencies seen near Earth (typically ~30kHz) then there must be direct field line connection from theacceleration region to Earth (Cane et al., 2002)