Properties of SEPs effective CMEs during solar cycle 23

Abstract

Seventy five large solar energetic particle (LSEP) events of different groups of proton intensity have been investigated during 1997-2005. It is observed that proton intensity increases linearly with increase in velocity of SEPs effective coronal mass ejections (CMEs). Further, for proton intensity I > 350 pfu, most of the SEPs effective CMEs are associated with X class of X-ray flares; whereas, for proton intensity I< 350 pfu, the SEPs effective CMEs are associated mainly with M and C class of X-ray flares. Furthermore, most of the CMEs are of halo type and occur mostly in western hemisphere for proton intensity I>350 pfu; whereas, for proton intensity I<350 pfu, CMEs observed in the eastern hemisphere are equally important. The association of SEPs effective CMEs has been observed better for longer wavelength, i.e. Decameter – Hectometer (DH) Type II radio bursts than shorter wavelength, i.e. metric (m) Type II radio bursts.