SEPs and CMEs during Cycle 23

P. Makela¹, N. Gopalswamy², S. Yashiro³, S. Akiyama¹, H. Xie¹, E. Valtonen⁴

¹The Catholic University of America, Washington, DC 20064, USA
²NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA
³Interferometrics, Herndon, VA 20171, USA
⁴Department of Physics and Vaisala Institute for Space Physics and Astronomy, University of Turku, FI-20014 Turku, Finland

We present a study of solar energetic particle (SEP) abundances and their correlations with coronal mass ejections (CMEs) and the ensuing interplanetary disturbances. The measurements by the LASCO coronagraph and the ERNE particle detector, both on board the SOHO spacecraft, cover the years 1996-2007. We study the properties of SEP flux and the associated CMEs and the evolution of the properties during solar cycle 23. The SEP abundances can reveal essential information about the origin of the solar energetic particles and CMEs. CMEs that are both geoeffective and SEPeffective constitute an especially interesting subgroup of solar events.