Analysis of IMF fluctuations during solar energetic particle and magnetic storm events

Signatures of high flux solar energetic particle (SEP) events related to strong magnetic storms in the interplanetary magnetic field (IMF) fluctuation were investigated. Events were identified with SEP proton flux from 15000 to 30,000 pfu (> 10 MeV proton) and Dst value less than -150 nT. The SEP proton flux data is from NOAA and the IMF data is from ACE. Several storm dates have been selected which meet the criteria. A high correlation coefficient (r~.9) between the SEP flux and the IMF 4-min sigma B distribution tail feature (the number of peaks in the pre-storm 6-hr period) was obtained. The dB-rms data was also considered. Together with our previous result that a similar high correlation existed between the peak Dst value during the storm and the IMF 4-min sigma B distribution tail feature in the pre-storm 6-hr period (AMS-Space Weather symposium 2004, Seattle, paper 3.9), this paper concludes that the IMF distribution tail feature is a significant characteristic of the fluctuation. The tail feature could serve as a marker for SEP diffusion through the IMF. Diffusion of SEP from solar flares and Coronal Mass Ejections (CME) will be considered, as in our paper 3.11 of the AMS 2004 symposium, now with consideration of the IMF direction and strength before and during the events. Application to medium SEP proton flux (~ 2000 pfu) events such as the Nov 4, 2003 and Jan 20, 2005 events will be discussed.