Solar Energetic Particle Events in the 23rd Solar Cycle: Interplanetary Magnetic Field Configuration and Statistical Relationship with Flares and CMEs |
|
Rositsa Miteva Submitted: 2014-02-27 01:54
We study the influence of the large-scale interplanetary magneticfield configuration on the solar energetic particles (SEPs) asdetected at different satellites near Earth and on the correlation oftheir peak intensities with the parent solar activity. We selected SEPevents associated with X- and M-class flares at western longitudes, inorder to ensure good magnetic connection to Earth. These events wereclassified into two categories according to the global interplanetarymagnetic field (IMF) configuration present during the SEP propagationto 1 AU: standard solar wind or interplanetary coronal mass ejections(ICMEs). Our analysis shows that around 20 % of all particle eventsare detected when the spacecraft is immersed in an ICME. Thecorrelation of the peak particle intensity with the projected speed ofthe SEP-associated coronal mass ejection is similar in the two IMFcategories of proton and electron events, ≈ 0.6. The SEP eventswithin ICMEs show stronger correlation between the peak protonintensity and the soft X-ray flux of the associated solar flare, withcorrelation coefficient r=0.67±0.13, compared to the SEP eventspropagating in the standard solar wind, r=0.36±0.13. The difference ismore pronounced for near-relativistic electrons. The main reason forthe different correlation behavior seems to be the larger spread ofthe flare longitude in the SEP sample detected in the solar wind ascompared to SEP events within ICMEs. We discuss to what extentobservational bias, different physical processes (particle injection,transport, etc.), and the IMF configuration can influence therelationship between SEPs and coronal activity.
Authors: Miteva, R.; Klein, K.-L.; Malandraki, O.; Dorrian, G.
Projects: GOES Particles
|
Publication Status: Solar Physics (accepted)
Last Modified: 2014-03-07 03:57
|
 
 
 
 
|
|