Acceleration of Solar Energetic Particles in CME-Driven Coronal Shocks up to 30 Rs

2021 ◽  
Author(s):  
Kamen Kozarev ◽  
Mohamed Nedal ◽  
Rositsa Miteva ◽  
Pietro Zucca ◽  
Momchil Dechev
Keyword(s):  
Emission Measure ◽  
Realistic Model ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Shock Acceleration ◽  
Quiet Time ◽  
Diffusive Shock Acceleration ◽  
Important Region ◽  
Wave Surfaces ◽  
Mass Ejection

<p>The lower and middle solar corona up to about 30 solar radii is thought to be an important region for early acceleration and transport of solar energetic particles (SEPs) by coronal mass ejection-driven shock waves. There, these waves propagate into a highly variable dynamic medium with steep gradients and rapidly expanding coronal magnetic fields, which modulates the particle acceleration near the shock/wave surfaces, and the way SEPs spread into the heliosphere. We present a study modeling the acceleration of SEPs in over 50 separate global coronal shock events between 1 and 30 solar radii. As part of the SPREAdFAST framework project, we analyzed the interaction of off-limb coronal bright fronts (CBF) observed with the SDO/AIA EUV telescope with realistic model coronal plasma based on results from synoptic magnetohydrodynamic (MHD) and differential emission measure (DEM) models. We used realistic quiet-time proton spectra observed near Earth to form seed suprathermal populations accelerated in our diffusive shock acceleration model (Kozarev & Schwadron, 2016). We summarize our findings and present implications for nowcasting SEP acceleration and heliospheric connectivity.</p>

SOLAR ENERGETIC PARTICLES

2005 ◽  
Vol 20 (29) ◽  
pp. 6634-6641
Author(s):  
PÉTER KIRÁLY
Keyword(s):  
Solar Cycle ◽  
Interplanetary Space ◽  
Energetic Particles ◽  
Vital Role ◽  
Solar Energetic Particles ◽  
Interstellar Space ◽  
Interplanetary Shocks ◽  
Quiet Time ◽  
Solar Origin ◽  
Suprathermal Particles

Energetic particles recorded in the Earth environment and in interplanetary space have a multitude of origins, i.e. acceleration and propagation histories. At early days practically all sufficiently energetic particles were considered to have come either from solar flares or from interstellar space. Later on, co-rotating interplanetary shocks, the termination shock of the supersonic solar wind, planetary bow shocks and magnetospheres, and also coronal mass ejections (CME) were recognized as energetic particle sources. It was also recognized that less energetic (suprathermal) particles of solar origin and pick-up ions have also a vital role in giving rise to energetic particles in interplanetary disturbances. The meaning of the term "solar energetic particles" (SEP) is now somewhat vague, but essentially it refers to particles produced in disturbances fairly directly related to solar processes. Variation of intensity fluctuations with energy and with the phase of the solar cycle will be discussed. Particular attention will be given to extremes of time variation, i.e. to very quiet periods and to large events. While quiet-time fluxes are expected to shed light on some basic coronal processes, large events dominate the fluctuation characteristics of cumulated fluence, and the change of that fluctuation with energy and with the phase of the solar cycle may also provide important clues. Mainly ISEE-3 and long-term IMP-8 data will be invoked. Energetic and suprathermal particles that may never escape into interplanetary space may play an important part in heating the corona of the sun.

scholarly journals THE VERY UNUSUAL INTERPLANETARY CORONAL MASS EJECTION OF 2012 JULY 23: A BLAST WAVE MEDIATED BY SOLAR ENERGETIC PARTICLES

2013 ◽  
Vol 770 (1) ◽  
pp. 38 ◽  
Author(s):  
C. T. Russell ◽  
R. A. Mewaldt ◽  
J. G. Luhmann ◽  
G. M. Mason ◽  
T. T. von Rosenvinge ◽  
...  
Keyword(s):  
Coronal Mass Ejection ◽  
Blast Wave ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Interplanetary Coronal Mass Ejection ◽  
Mass Ejection

scholarly journals Simulation of a CME-driven shock by anisotropic scattering angular distributions

2012 ◽  
Vol 8 (S294) ◽  
pp. 583-584
Author(s):  
Xin Wang ◽  
Yi-Hua Yan
Keyword(s):  
Monte Carlo Simulation ◽  
Cosmic Ray ◽  
Interplanetary Shock ◽  
Anisotropic Scattering ◽  
Particle Energy ◽  
Angular Distributions ◽  
Shock Acceleration ◽  
Diffusive Shock Acceleration ◽  
Mass Ejection ◽  
Mev Protons

AbstractObservations of the interplanetary shock provide us with strong evidences of particle acceleration to multi-MeV protons in a coronal mass ejection (CME). Diffusive shock acceleration (DSA) is an efficient mechanism for cosmic ray (CR). This work presents a dynamical Monte Carlo simulation of a CME-driven shock on 14-Dec-2006 by using a series of Gaussian scattering angular distributions. With the simulated results, we find that particle energy spectrum is affected by energy injection processes under the anisotropic scattering law.

scholarly journals Propagation of Solar Energetic Particles During Multiple Coronal Mass Ejection Events

Solar Physics ◽  
2016 ◽  
Vol 291 (2) ◽  
pp. 487-511 ◽  
Author(s):  
Silja Pohjolainen ◽  
Firas Al-Hamadani ◽  
Eino Valtonen
Keyword(s):  
Coronal Mass Ejection ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Mass Ejection

scholarly journals ULYSSES observations of energetic particle acceleration and the superposed CME and CIR events of November 1992

1996 ◽  
Vol 14 (4) ◽  
pp. 400-410 ◽  
Author(s):  
T. L. Lim ◽  
J. J. Quenby ◽  
M. K. Reuss ◽  
E. Keppler ◽  
H. Kunow ◽  
...  
Keyword(s):  
Energetic Particle ◽  
High Energy ◽  
Alpha Particles ◽  
Alternative Possibilities ◽  
Shock Acceleration ◽  
Diffusive Shock Acceleration ◽  
Magnetometer Data ◽  
Proton Data ◽  
Mass Ejection ◽  
Unique Study

Abstract. During November 1992, a series of forward and reverse shocks passed the ULYSSES spacecraft. Spectral and anisotropy measurements are reported for protons and alpha particles between 0.28 and 6 MeV observed by the Energetic Particle Composition Experiment, data recorded by the Magnetometer Experiment and the high-energy (2.7–300 MeV) proton data from the Kiel Electron Telescope. An analysis of energetic particle, plasma and magnetometer data from ULYSSES has allowed a unique study of the corresponding arrival of fare particles, particles within a corotating interaction region and particles transported with a coronal mass ejection. We present an analysis of these data in terms of possible diffusive shock acceleration but conclude that this is likely to be incompatible with the short transit time of the particles. Shock drift acceleration of particles with energies 0.3 MeV/nucleon or solar acceleration followed by particle trapping behind the shock front are alternative possibilities.

scholarly journals Sixty Years of Element Abundance Measurements in Solar Energetic Particles

2021 ◽  
Vol 217 (6) ◽  
Author(s):  
Donald V. Reames
Keyword(s):  
Solar Corona ◽  
Magnetic Reconnection ◽  
Extreme Ultraviolet ◽  
Chemical Elements ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Charge Ratio ◽  
Element Abundance ◽  
Shock Acceleration ◽  
Element Abundances

AbstractSixty years ago the first observation was published showing solar energetic particles (SEPs) with a sampling of chemical elements with atomic numbers $6 \leq Z \leq 18$ 6 ≤ Z ≤ 18 above 40 MeV amu−1. Thus began study of the direct products of dynamic physics in the solar corona. As we have progressed from 4-min sounding-rocket samples to continuous satellite coverage of SEP events, we have extended the observations to the unusual distribution of element abundances throughout the periodic table. Small “impulsive” SEP events from islands of magnetic reconnection on open magnetic-field lines in solar jets generate huge enhancements in abundances of 3He and of the heaviest elements, enhancements increasing as a power of the ion mass-to-charge ratio as ($A$ A /$Q$ Q )3.6, on average. Solar flares involve the same physics but there the SEPs are trapped on closed loops, expending their energy as heat and light. The larger, energetic “gradual” SEP events are accelerated at shock waves driven by fast, wide coronal mass ejections (CMEs). However, these shocks can also reaccelerate ions from pools of residual suprathermal impulsive ions, and CMEs from jets can also drive fast shocks, complicating the picture. The underlying element abundances in SEP events represent the solar corona, which differs from corresponding abundances in the photosphere as a function of the first ionization potential (FIP) of the elements, distinguishing low-FIP (<10 eV) ions from high-FIP neutral atoms as they expand through the chromosphere. Differences in FIP patterns of SEPs and the solar wind may distinguish closed- and open-field regions of formation at the base of the corona. Dependence of SEP acceleration upon $A$ A /$Q$ Q allows best-fit estimation of ion $Q$ Q -values and hence of the source plasma temperature of ∼1 – 3 MK, derived from abundances, which correlates with recent measures of temperatures using extreme ultraviolet emission from jets. Thus, element abundances in SEPs have become a powerful tool to study the underlying solar corona and to probe physical processes of broad astrophysical significance, from the “FIP effect” to magnetic reconnection and shock acceleration. New questions arise, however, about the theoretical basis of correlations of energy-spectral indices with power-laws of abundances, about the coexistence of separate resonant and non-resonant mechanisms for enhancements of 3He and of heavy elements, about occasional events with unusual suppression of He and about the overall paucity of C in FIP comparisons.

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