Title: The April 15 and 18, 2001 Solar Energetic Particle Events recorded by the LION instrument on SOHO, and associated Ground Level Events recorded at medium latitudes
Author: Karoly Kecskemety
Affil: KFKI Research Institute for Particle and Nuclear Physics, Budapest, Hungary
Email: kecske@rmki.kfki.hu
Authors: S. McKenna-Lawlor, K. Kudela
Affils: Space Technology Ireland, National University of Ireland, Maynooth, Co. Kildare, Ireland; Institute for Experimental Physics, Kosice, Slovakia
Abstract: A class X14.4 flare on April 15, 2001, at 1350 UT in active region 9415, together with an accompanying CME were followed by (a) a large solar energetic particle event recorded by the LION instrument on SOHO and (b) large Ground Level Events starting at 1400 UT which were observed by neutron monitors world-wide. An interplanetary shock wave reached the Earth at 0048 UT on April 18, stimulating a high value of the Kp index. The particle signatures exhibited a fresh injection from the same active region starting at 0215 UT on April 18 (a C2 flare and a CME). These events were followed by a further, smaller GLE from 0242 UT. Observations made by the energetic particle experiment LION aboard SOHO and by the Lomnicky Stit Neutron Monitor on the days concerned, are presented and discussed.