Whistler waves observed by Solar Orbiter / RPW between 0.5 AU and 1 AU

Abstract

The goal of our study is to detect and characterize the electromagnetic waves that can modify the electron distribution functions, with a special attention to whistler waves. We analyse in details the electric and magnetic field fluctuations observed by the Solar Orbiter spacecraft during its first orbit around the Sun between 0.5 and 1 AU. Using data of the Search Coil Magnetometer and electric antenna, both parts of the Radio and Plasma Waves (RPW) instrumental suite, we detect the electromagnetic waves with frequencies above 3 Hz and determine the statistical distribution of their amplitudes, frequencies, polarization and k-vector as a function of distance. We also discuss relevant instrumental issues regarding the phase between the electric and magnetic measurements and the effective length of the electric antenna. An overwhelming majority of the observed waves are right hand circularly polarized in the solar wind frame and identified as outward propagating and quasi parallel whistler waves. Their occurrence rate increases by a least a factor two from 1 AU to 0.5 AU. These results are consistent with the regulation of the heat flux by the whistler heat flux instability. Near 0.5 AU, whistler waves are found to be more field-aligned and to have smaller normalized frequency ($f/f_{ce}$), larger amplitude, and larger bandwidth than at 1 AU.

accepted in A&A

References in corpus (11)

• 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
• Experimental determination of whistler wave dispersion relation in the solar wind
• Whistler wave generation by halo electrons in the solar wind
• Sunward propagating whistler waves collocated with localized magnetic field holes in the solar wind: Parker Solar Probe observations at 35.7 Sun radii
• Electron heat flux in the near-Sun environment
• Density Fluctuations Associated with Turbulence and Waves: First Observations by Solar Orbiter
• Whistler wave occurrence and the interaction with strahl electrons during the first encounter of Parker Solar Probe
• Whistler Waves and Electron Properties in the Inner Heliosphere: Helios Observations
• On quasi-parallel whistler waves in the solar wind
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Cited by in corpus (12)

• Density Fluctuations Associated with Turbulence and Waves: First Observations by Solar Orbiter
• Kinetic Electrostatic Waves and their Association with Current Structures in the Solar Wind
• Whistler instability driven by the sunward electron deficit in the solar wind
• Solar wind current sheets and deHoffmann-Teller analysis: First results of DC electric field measurements by Solar Orbiter
• Whistler Wave Observations by \textit{Parker Solar Probe} During Encounter $1$: Counter-Propagating Whistlers Collocated with Magnetic Field Inhomogeneities and their Application to Electric Field Measurement Calibration
• Whistler waves generated inside magnetic dips in the young solar wind: observations of the Search-Coil Magnetometer on board Parker Solar Probe
• The Stability of the Electron Strahl against the Oblique Fast-magnetosonic/Whistler Instability in the Inner Heliosphere
• Quantifying the diffusion of suprathermal electrons by whistler waves between 0.2 and 1 AU with Solar Orbiter and Parker Solar Probe
• Whistler waves in the young solar wind: statistics of amplitude and propagation direction from Parker Solar Probe Encounters 1-11
• Reconstruction of Polarization Properties of Whistler Waves From Two Magnetic and Two Electric Field Components: Application to Parker Solar Probe Measurements
• Particle-In-Cell Simulations of Sunward and Anti-sunward Whistler Waves in the Solar Wind
• Quasi-parallel anti-sunward propagating whistler waves associated to the electron-deficit in the near-Sun solar wind: Particle-in-Cell simulation