Observations Of Solar Energetic Particles And Coronal Mass Ejection Driven Shocks

Solar energetic particles(SEPs),with the energies ranging from a few keV to several GeV,are one population of particle streams produced by the rapid release of magnetic energy during solar eruptions.Since its discovery by the ground-based instruments in 1942,many researches in solar physics focus on this field,and it has become one of the most active research fields of space science.Meanwhile,due to its hazard on the Earth and human life,the researches on SEPs are significant to the practical applications.Since the paper,"The flare myth"[1],has been published,the two-divided diagram about the source of SEPs,flare and CME driven shocks,has been established and well developed.While,there are still some problems unsolved.For example,which process,flare or CME,dominates the impulsive phase of gradual SEP events,when and where the energetic particles are released during the start time of SEP events.Based on the former work and the increasing number of new data and multi-wavelength observations,we hope to have a detailed discussion on those problems.In order to answer the question which process dominates the impulsive phase of gradual SEP events,we carried out study on the SEP event occured on August 9,2011.The multi-wavelength remote-sensing observations and the in-site measurements on the space instruments were analyzed.Also,the solar particle release(SPR)time,the spectra of particles and Hard X-ray emission are derived.We concluded that the coronal shock wave should be responsible for this event.Apart from this,the release time of electrons are earlier than the protons.We then carried out a statistical analysis for the 32 SEP events that occurred between 2010 and 2014.The CME observed from three viewpoints including SOHO/LASCO,and Cor2 on board the STA/B are fitted by the Graduated-Cylindrical-shell(GCS)model and the precise evolution of CME are obtained.Combining the in-situ measurements,we found that there is an average delay of proton release relative to electrons,up to 6.4 minutes.At the same time,the average release height of electrons are 5.87 solar radii,0.37 solar radius lower than the proton released height.For the protons and electrons with similar velocities,the release time discrepancy between those two channels is about 15 minutes.The reason should be the scattering transportation of different particles in interplanetary space.