Corotating Shock Waves and the Solar-Wind Source of Energetic Ion Abundances: Power Laws in A/Q

Abstract

We find that element abundances in energetic ions accelerated by shock waves formed at corotating interaction regions (CIRs) mirror the abundances of the solar wind modified by a decreasing power-law dependence on the mass-to-charge ratio A/Q of the ions. This behavior is similar in character to the well-known power-law dependence on A/Q of abundances in large gradual solar energetic particles (SEP). The CIR ions reflect the pattern of A/Q, with Q values of the source plasma temperature or freezing-in temperature of 1.0 - 1.2 MK typical of the fast solar wind in this case. Thus the relative ion abundances in CIRs are of the form (A/Q)**a where a is nearly always negative and evidently decreases with distance from the shocks, which usually begin beyond 1 AU. For one unusual historic CIR event where a ~ 0, the reverse shock wave of the CIR seems to occur at 1 AU, and these abundances of the energetic ions become a direct proxy for the abundances of the fast solar wind.

19 pages, 7 figures, accepted by Solar Phys

References in corpus (5)

• Abundance Enhancements in Impulsive Solar Energetic-Particle Events with Associated Coronal Mass Ejections
• The First Ionization Potential Effect from the Ponderomotive Force: On the Polarization and Coronal Origin of the Alfven Waves
• Abundances, Ionization States, Temperatures, and FIP in Solar Energetic Particles
• The "FIP Effect" and the Origins of Solar Energetic Particles and of the Solar Wind
• Abundances of Suprathermal Heavy Ions in CIRs during the Minimum of Solar Cycle 23

Cited by in corpus (8)

• Solar Energetic Particles (Second Edition)
• Four Distinct Pathways to the Element Abundances in Solar Energetic Particles
• Energetic Particle Increases Associated with Stream Interaction Regions
• Hydrogen and the Abundances of Elements in Gradual Solar Energetic-Particle Events
• Helium Suppression in Impulsive Solar Energetic-Particle Events
• Excess H, Suppressed He, and the Abundances of Elements in Solar Energetic Particles
• Solar Cycle Variation of 0.3-1.29 MeV/nucleon Heavy Ion Composition during Quiet Times near 1 AU in Solar Cycles 23 and 24
• Element Abundances of Solar Energetic Particles and the Photosphere, the Corona, and the Solar Wind