Related papers: Triggered ion acoustic waves in the solar wind

The Parker Solar Probe is in a solar orbit with a perihelion for orbit 12 at 13.3 solar radii. The electric field experiment on this satellite observes what we call triggered ion-acoustic waves as the most dominant wave mode above a few Hz…

Triggered ion-acoustic waves are a pair of coupled waves observed in the previously unexplored plasma regime near the Sun. They may be capable of producing important effects on the solar wind. Because this wave mode has not been observed or…

Electric field measurements of the Time Domain Sampler (TDS) receiver, part of the Radio and Plasma Waves (RPW) instrument on board Solar Orbiter, often exhibit very intense broadband wave emissions at frequencies below 20~kHz in the…

This work reports a novel plasma wave observation in the near-Sun solar wind: frequency-dispersed ion acoustic waves. Similar waves were previously reported in association with interplanetary shocks or planetary bow shocks, but the waves…

This study is motivated by recent observations from the Parker Solar Probe (PSP) mission, which have been identified as the ion-acoustic waves from 15 to 25 solar radii. These observations reveal characteristic sequences of narrow-band,…

This letter describes a new phenomenon on the Parker Solar Probe of recurring plasma density enhancements that have $\Delta$n/n ~10% and that occur at a repetition rate of ~5 Hz. They were observed sporadically for about five hours between…

A variety of kinetic waves develop in the solar wind. The relationship between these waves and larger-scale structures, such as current sheets and ongoing turbulence remain a topic of investigation. Similarly, the instabilities producing…

Parker Solar Probe measurements have recently shown that coherent fast magnetosonic and Alfv\'{e}n ion-cyclotron waves are abundant in the solar wind and can be accompanied by higher-frequency electrostatic fluctuations. In this letter we…

Understanding the physical processes in the solar wind and corona which actively contribute to heating, acceleration, and dissipation is a primary objective of NASA's Parker Solar Probe (PSP) mission. Observations of coherent…

Wave emissions at frequencies near electron gyrofrequency harmonics are observed at small heliocentric distances below about 40 solar radii and are known to occur in regions with quiescent magnetic fields. We show the close connection of…

AIM: Large amplitude narrowband obliquely propagating whistler-mode waves at frequencies of ~0.2 fce (electron cyclotron frequency) are commonly observed at 1 AU, and are most consistent with the whistler heat flux fan instability. We want…

Orbits six through nine of the Parker Solar Probe have been studied to show that solar wind core electrons emerged from 15 solar radii with temperatures that were constant to within ~10% although the solar wind speed varied from 300 to 800…

Perihelion passes on Parker Solar Probe orbits six through nine have been studied to show that solar wind core electrons emerged from 15 solar radii with a temperature of 55 plus or minus 5 eV, independent of the solar wind speed which…

The largest electric fields between 18 and 30 solar radii are in narrow band waves simultaneously observed at a few Hz (somewhat above the local proton gyrofrequency) and a few hundred Hz (far below the lower hybrid frequency), with the…

Observations of plasma waves by the Fields Suite and of electrons by the Solar Wind Electrons Alphas and Protons Investigation (SWEAP) on Parker Solar Probe provide strong evidence for pitch angle scattering of strahl-energy electrons by…

Determining the mechanism responsible for the plasma heating and particle acceleration is a fundamental problem in the study of the heliosphere. Due to efficient wave-particle interactions of ion-scale waves with charged particles, these…

Recent in situ observations from Parker Solar Probe (PSP) near perihelia reveal ion beams, temperature anisotropies, and kinetic wave activity. These features are likely linked to solar wind heating and acceleration. During PSP Encounter 17…

Parker Solar Probe (PSP), NASA's latest and closest mission to the Sun, is on a journey to investigate fundamental enigmas of the inner heliosphere. This paper reports initial observations made by the Solar Probe Analyzer for Ions (SPAN-I),…

Circularly polarized, nearly parallel propagating waves are prevalent in the solar wind at ion-kinetic scales. At these scales, the spectrum of turbulent fluctuations in the solar wind steepens, often called the transition-range, before…

During Parker Solar Probe (Parker) Encounter 15 (E15), we observe an 18-hour period of near subsonic ($\mathrm{M_S \sim}$ 1) and sub-Alfv\'enic (SA), $\mathrm{M_A}$ <<< 1, slow speed solar wind from 22 to 15.6 R$_\odot$. As the most extreme…