Modeling interactions of narrowband large amplitude whistler-mode waves with electrons in the solar wind inside ~.3 AU and at 1 AU using a particle tracing code

Abstract

The discovery of large-amplitude narrowband whistler-mode waves at frequencies of tenths of the electron cyclotron frequency in large numbers both inside ~.3 AU and at ~1 AU provides an answer to longstanding questions about scattering and energization of solar wind electrons. The waves can have rapid nonlinear interactions with electrons over a broad energy range. Counter-propagation between electrons and waves is not required for resonance with the obliquely propagating waves in contrast to the case for parallel propagation. Using a full 3d particle tracing code, we have examined interactions of electrons with energies from 0 eV to 2 keV with whistler-mode waves with amplitudes of 20 mV/m and propagation angles from 0 to 180 degrees to the background magnetic field. Interactions with wave packets and single waves are both modeled based on observations at ~.3 AU and 1 AU. The simulations demonstrate the key role played by these waves in rapid scattering and energization of electrons. Results provide evidence for nonlinear effects, indicating that quasi-linear methods are not adequate for modeling the role of whistlers in the evolution of solar wind electrons. Strong scattering and energization for some initial energy and pitch angle ranges occurs for both counter-propagating and obliquely propagating waves. The strong scattering of strahl electrons counteracts the pitch angle narrowing due to conservation of the first adiabatic invariant as electrons propagate away from the sun into regions of smaller magnetic field. Scattering also produces the hotter isotropic halo. The concomitant limiting of the electron heat flux is also relevant in other astrophysical settings.

References in corpus (5)

• Electrons in the Young Solar Wind: First Results from the Parker Solar Probe
• Whistler mode waves and the electron heat flux in the solar wind: Cluster observations
• Statistical Study of Whistler Waves in the Solar Wind at 1 AU
• Parker Solar Probe evidence for scattering of electrons in the young solar wind by narrowband whistler-mode waves
• Solar Multiple Eruptions From a Confined Magnetic Structure

Cited by in corpus (6)

• Parker Solar Probe: Four Years of Discoveries at Solar Cycle Minimum
• Whistler waves generated inside magnetic dips in the young solar wind: observations of the Search-Coil Magnetometer on board Parker Solar Probe
• Quantifying the diffusion of suprathermal electrons by whistler waves between 0.2 and 1 AU with Solar Orbiter and Parker Solar Probe
• Stochastic diffusion of electrons interacting with whistler-mode waves in the solar wind
• Reconstruction of Polarization Properties of Whistler Waves From Two Magnetic and Two Electric Field Components: Application to Parker Solar Probe Measurements
• Parker Solar Probe evidence for the absence of whistlers close to the Sun to scatter strahl and regulate heat flux