Related papers: Ion-Driven Instabilities in the Inner Heliosphere …
Instabilities described by linear theory characterize an important form of wave-particle interaction in the solar wind. We diagnose unstable behavior of solar wind plasma between 0.3 and 1 au via the Nyquist criterion, applying it to fits…
Analysis of ion-kinetic instabilities in solar wind plasmas is crucial for understanding energetics and dynamics throughout the heliosphere, as evident from spacecraft observations of complex ion velocity distribution functions (VDFs) and…
Wave-particle instabilities driven by departures from local thermodynamic equilibrium have been conjectured to play a role in governing solar wind dynamics. We calculate the statistical variation of linear stability over a large subset of…
Differential flows among different ion species are often observed in the solar wind, and such ion differential flows can provide the free energy to drive Alfv\'en/ion-cyclotron and fast-magnetosonic/whistler instabilities. Previous works…
The hot and diffuse nature of the Sun's extended atmosphere allows it to persist in non-equilibrium states for long enough that wave-particle instabilities can arise and modify the evolution of the expanding solar wind. Determining which…
In-situ observations of the solar wind (SW) plasma from 0.29 to 1AU show that the protons and alpha particles are often non-Maxwellian, with evidence of kinetic instabilities, temperature anisotropies, differential ion streaming, and…
Observations of solar wind velocity distribution functions (VDFs) commonly reveal fine-scale structures. These features strongly influence kinetic processes such as wave damping and instability, yet their role remains poorly understood. We…
The heliosphere is predominantly a partially ionized plasma that consists of electrons, ions and significant neutral atoms. Nonlinear interactions amongst these species take place through direct collision or charge exchange processes. These…
Important efforts are currently made for understanding the so-called kinetic instabilities, driven by the anisotropy of different species of plasma particles present in the solar wind and terrestrial magnetosphere. These instabilities are…
The expanding solar wind plasma ubiquitously exhibits anisotropic non-thermal particle velocity distributions. Typically, proton Velocity Distribution Functions (VDFs) show the presence of a core and a field-aligned beam. Novel observations…
Recent in-situ observations from the Parker Solar Probe (PSP) mission in the inner heliosphere near perihelia show evidence of ion beams, temperature anisotropies, and kinetic wave activity, which are likely associated with kinetic heating…
The stability of weakly collisional plasmas is well represented by linear theory, and the generated waves play an essential role in the thermodynamics of these systems. The velocity distribution functions (VDF) characterizing kinetic…
Past observations show that solar wind (SW) acceleration occurs inside the sub-Alfvenic region, reaching the local Alfven speed at typical distances ~ 10 - 20 Rs (solar radii). Recently, Parker Solar Probe (PSP) traversed regions of…
In this work, we investigate how the complex structure found in solar wind proton velocity distribution functions (VDFs), rather than the commonly assumed two-component bi-Maxwellian structure, affects the onset and evolution of…
Firehose-like instabilities (FIs) are cited in multiple astrophysical applications. Of particular interest are the kinetic manifestations in weakly-collisional or even collisionless plasmas, where these instabilities are expected to…
We study the linear stability of weakly magnetized differentially rotating plasmas in both collisionless kinetic theory and Braginskii's theory of collisional, magnetized plasmas. We focus on the very weakly magnetized limit that is…
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…
Ion-driven plasma instability thresholds, derived from linear theory, constrain the distribution of solar observations in parameter space, defining boundaries of stable plasma parameters. Excursions beyond these thresholds result in the…
In this paper, weak turbulence theory is used to investigate the nonlinear evolution of the parametric instability in 3D low-$\beta$ plasmas at wavelengths much greater than the ion inertial length under the assumption that slow…
We perform a statistical assessment of solar wind stability at 1 AU against ion sources of free energy using Nyquist's instability criterion. In contrast to typically employed threshold models which consider a single free-energy source,…