Ponderomotive Acceleration in Coronal Loops

Abstract

Ponderomotive acceleration has been asserted to be a cause of the First Ionization Potential (FIP) effect, the by now well known enhancement in abundance by a factor of 3-4 over photospheric values of elements in the solar corona with FIP less than about 10 eV. It is shown here by means of numerical simulations that ponderomotive acceleration occurs in solar coronal loops, with the appropriate magnitude and direction, as a "byproduct" of coronal heating. The numerical simulations are performed with the HYPERION code, which solves the fully compressible three-dimensional magnetohydrodynamic equations including nonlinear thermal conduction and optically thin radiation. Numerical simulations of a coronal loops with an axial magnetic field from 0.005 Teslas to 0.02 Teslas and lengths from 25000 km to 75000 km are presented. In the simulations the footpoints of the axial loop magnetic field are convected by random, large-scale motions. There is a continuous formation and dissipation of field-aligned current sheets which act to heat the loop. As a consequence of coronal magnetic reconnection, small scale, high speed jets form. The familiar vortex quadrupoles form at reconnection sites. Between the magnetic footpoints and the corona the reconnection flow merges with the boundary flow. It is in this region that the ponderomotive acceleration occurs. Mirroring the character of the coronal reconnection, the ponderomotive acceleration is also found to be intermittent.

14 pages, 19 figures, accepted by the Astrophysical Journal

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Cited by in corpus (19)

• Kink oscillations of coronal loops
• Element Abundances: A New Diagnostic for the Solar Wind
• The First Ionization Potential Effect from the Ponderomotive Force: On the Polarization and Coronal Origin of the Alfven Waves
• The FIP and Inverse FIP Effects in Solar Flares
• Coronal Elemental Abundances in Solar Emerging Flux Regions
• Alfvenic Perturbations in a Sunspot Chromosphere Linked to Fractionated Plasma in the Corona
• Linking the Sun to the Heliosphere Using Composition Data and Modelling. A Test Case with a Coronal Jet
• The impact of multi-fluid effects in the solar chromosphere on the ponderomotive force under LTE and NEQ ionization conditions
• Coronal Elemental Abundances during A-class Solar Flares Observed by Chandrayaan-2 XSM
• Determining the Elemental and Isotopic Composition of the preSolar Nebula from Genesis Data Analysis: The Case of Oxygen
• Observations of the Quiet Sun During the Deepest Solar Minimum of the Past Century with Chandrayaan-2 XSM -- Elemental Abundances in the Quiescent Corona
• Energetics and 3-D Structure of Elementary Events in Solar Coronal Heating
• On the Origin of Magnetic Pertubations associated with the FIP effect
• Evolution of Plasma Composition in an Eruptive Flux Rope
• Magnetic Field Geometry and Composition Variation in Slow Solar Winds: The Case of Sulfur
• Element Abundances in Impulsive Solar Energetic Particle Events
• Disparity among low first ionization potential elements
• Evolution of Elemental Abundances During B-Class Solar Flares: Soft X-ray Spectral Measurements with Chandrayaan-2 XSM
• FIP Bias Evolution in an Emerging Active Region as observed in SPICE Synoptic Observations