Modeling a Single SEP Event from Multiple Vantage Points Using the iPATH Model

Hu, Junxiang; Li, Gang; Fu, Shuai; Zank, G. P.; Ao, Xianzhi

doi:10.3847/2041-8213/aaabc1

Cited by 35 publications

(46 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We would speculate that a fast shock Ng and Reames ( 2008) solved the self-consistent time-dependent wave-particle interaction while Zank et al (2000) used a series of instantaneous steady-state solutions in their PATH (Particle Acceleration and Transport in the Heliosphere) model. The latter simplicity gave a better determination of maximum particle energies of GeV and allowed the inclusion of more-realistic two-dimensional versions of the CME and shock in the PATH models, including oblique shocks (Li et al 2012) and perpendicular diffusion of the particles caused by random walk of the magnetic fields (Hu et al , 2018.…”

Section: Models and Shock Accelerationmentioning

confidence: 99%

Solar Energetic Particles

Reames

2017

Lecture Notes in Physics

View full text Add to dashboard Cite

Both monographs and multi-author volumes will be considered for publication. Edited volumes should however consist of a very limited number of contributions only. Proceedings will not be considered for LNP. Volumes published in LNP are disseminated both in print and in electronic formats, the electronic archive being available at springerlink.com. The series content is indexed, abstracted and referenced by many abstracting and information services, bibliographic networks, subscription agencies, library networks, and consortia.

show abstract

Section: Models and Shock Accelerationmentioning

confidence: 99%

Solar Energetic Particles

Reames

2017

Lecture Notes in Physics

View full text Add to dashboard Cite

show abstract

“…Ng and Reames (2008) solved the self-consistent time-dependent wave-particle interaction while Zank et al (2000) used a series of instantaneous steady-state solutions in their PATH (Particle Acceleration and Transport in the Heliosphere) model. The latter simplicity gave a better determination of maximum particle energies of GeV and allowed the inclusion of more-realistic two-dimensional versions of the CME and shock in the PATH models, including oblique shocks (Li et al 2012) and perpendicular diffusion of the particles caused by random walk of the magnetic fields (Hu et al 2017(Hu et al , 2018.…”

Section: Models and Shock Accelerationmentioning

confidence: 99%

Gradual SEP Events

Reames

2021

Solar Energetic Particles

View full text Add to dashboard Cite

Gradual solar energetic-particle (SEP) events are “big proton events” and are usually much more “gradual” in their decay than in their onset. As their intensities increase, particles streaming away from the shock amplify Alfvén waves that scatter subsequent particles, increasing their acceleration, eventually limiting ion flow at the “streaming limit.” Waves generated by higher-speed protons running ahead can also throttle the flow of lower-energy ions, flattening spectra and altering abundances in the biggest SEP events. Thus, we find that the A/Q-dependence of scattering causes element-abundance patterns varying in space and time, which define source-plasma temperatures T, since the pattern of Q values of the ions depends upon temperature. Differences in T explain much of the variation of element abundances in gradual SEP events. In nearly 70% of gradual events, SEPs are shock-accelerated from ambient coronal plasma of ~0.8–1.6 MK, while 24% of the events involve material with T ≈ 2–4 MK re-accelerated from residual impulsive-suprathermal ions with pre-enhanced abundances. This source-plasma temperature can occasionally vary with solar longitude across the face of a shock. Non-thermal variations in ion abundances in gradual SEP events reaccelerated from the 2–4 MK impulsive source plasma are reduced, relative to those in the original impulsive SEPs, probably because the accelerating shock waves sample a pool of ions from multiple jet sources. Late in gradual events, SEPs become magnetically trapped in a reservoir behind the CME where spectra are uniform in space and decrease adiabatically in time as the magnetic bottle containing them slowly expands. Finally, we find variations of the He/O abundance ratio in the source plasma of different events.

show abstract

“…In this case, the strongest acceleration is assumed to occur near the central region of the shock, where the shock is presumably strongest and the speed is likely to be highest, and tends to decline around on the flanks (see, e.g., Reames 1999). It is worth noting that the strongest acceleration typically reflects the geometry of the shock and magnetic field, which can also make the flanks important for accelerating particles (see, e.g., Tylka et al 2005;Zank et al 2006;Hu et al 2017Hu et al , 2018. As can be seen from panel (c) of Figure 5, there is a clear anisotropy of energetic particles, indicating that the energetic particles of this event are propagating predominantly outward from the Sun, which gives additional evidence that the energetic particles are likely accelerated remotely.…”

Section: Flankmentioning

confidence: 99%

PSP/IS$\odot$IS Observation of a Solar Energetic Particle Event Associated With a Streamer Blowout Coronal Mass Ejection During Encounter 6

Getachew,

McComas,

Joyce

et al. 2021

Preprint

View full text Add to dashboard Cite

In this paper we examine a low-energy SEP event observed by IS IS's Energetic Particle Instrument-Low (EPI-Lo) inside 0.18 AU on September 30, 2020. This small SEP event has a very interesting time profile and ion composition. Our results show that the maximum energy and peak in intensity is observed mainly along the open radial magnetic field. The event shows velocity dispersion, and strong particle anisotropies are observed throughout the event showing that more particles are streaming outward from the Sun. We do not see a shock in the in-situ plasma or magnetic field data throughout the event. Heavy ions, such as O and Fe were detected in addition to protons and 4He, but without significant enhancements in 3He or energetic electrons. Our analysis shows that this event is associated with a slow streamer-blowout coronal mass ejection (SBO-CME) and the signatures of this small CME event are consistent with those typical of larger CME events. The time-intensity profile of this event shows that PSP encountered the western flank of the SBO-CME. The anisotropic and dispersive nature of this event in a shockless local plasma give indications that these particles are most likely accelerated remotely near the Sun by a weak shock or compression wave ahead of the SBO-CME. This event may represent direct observations of the source of low-energy SEP seed particle population.

show abstract

Modeling a Single SEP Event from Multiple Vantage Points Using the iPATH Model

Cited by 35 publications

References 22 publications

Solar Energetic Particles

Solar Energetic Particles

Gradual SEP Events

PSP/IS$\odot$IS Observation of a Solar Energetic Particle Event Associated With a Streamer Blowout Coronal Mass Ejection During Encounter 6

Contact Info

Product

Resources

About