166 citations · 450 across the 22 of their papers we have counts for
23 papers
Ion-Scale Waves Regulated by Plasma Beta and Cross Helicity: Observational Evidence for the Helicity Barrier in Imbalanced Solar Wind Turbulence
G. Q. Zhao, R. Meyrand, H. Q. Feng +3
Ion-scale waves are believed to play an important role in heating of the solar corona and wind, though their generation mechanism remains unclear. Based on Parker Solar Probe obser…
The Second Quadratic Invariant of Astrophysical Gyrokinetics
Benjamin D. G. Chandran, Alfred Mallet, Romain Meyrand
We show that gyrokinetics in a spatially uniform equilibrium (or `astrophysical gyrokinetics') possesses a previously unknown quadratic invariant, which we call the gyrokinetic hel…
A Transport Theory of Turbulent Coronal Heating in General Geometry
Jonathan Squire, Benjamin D. G. Chandran, Toby Adkins +3
Magnetic geometry shapes how turbulence transports and dissipates energy in strongly magnetized plasmas. The solar corona, a maze of open and closed flux tubes with sharp transvers…
Asymptotic scaling theory of electrostatic turbulent transport in magnetised fusion plasmas
T. Adkins, I. G. Abel, M. Barnes +8
Turbulent transport remains one of the principal obstacles to achieving efficient magnetic confinement in fusion devices. Two of the dominant drivers of the turbulence are microsca…
Formation of Magnetic Switchbacks via expanding Alfvén Waves
Trevor A. Bowen, Alfred Mallet, Corina I. Dunn +8
Context. Large-amplitude inversions of the solar wind's interplanetary magnetic field have long been documented; however, observations from the Parker Solar Probe (PSP) mission hav…
Turbulent heating in collisionless low-beta plasmas: imbalance, Landau damping, and electron-ion energy partition
T. Adkins, R. Meyrand, J. Squire
An understanding of how turbulent energy is partitioned between ions and electrons in weakly collisional plasmas is crucial for modelling many astrophysical systems. Using theory a…
Intermittent, Reflection-Driven, Strong Imbalanced MHD Turbulence
B. D. G. Chandran, N. Sioulas, S. Bale +4
We develop a phenomenological model of strong imbalanced magnetohydrodynamic (MHD) turbulence that accounts for intermittency and the reflection of Alfven waves by spatial variatio…
Generalized Expanding-Box Formulations of Reduced Magnetohydrodynamics in the Solar Wind
Vincent David, Benjamin D. G. Chandran, Romain Meyrand +2
We derive a set of simplified equations that can be used for numerical studies of reduced magnetohydrodynamic turbulence within a small patch of the radially expanding solar wind.…
A Unified Phenomenology of Ion Heating in Low- Plasmas: Test-Particle Simulations
Zade Johnston, Jonathan Squire, Romain Meyrand
We argue that stochastic and resonant ion heating, often viewed as distinct processes in low- collisionless plasmas, are the far limits of a continuum controlled by nonlinear br…
Evidence for the helicity barrier from measurements of the turbulence transition range in the solar wind
J. R. McIntyre, C. H. K. Chen, J. Squire +2
The means by which the turbulent cascade of energy is dissipated in the solar wind, and in other astrophysical systems, is a major open question. It has recently been proposed that…
Extended Cyclotron Resonant Heating of the Turbulent Solar Wind
Trevor A. Bowen, Ivan Y. Vasko, Stuart D. Bale +8
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…
The effects of finite electron inertia on helicity-barrier-mediated turbulence
T. Adkins, R. Meyrand, J. Squire
Understanding the partitioning of turbulent energy between ions and electrons in weakly collisional plasmas is crucial for the accurate interpretation of observations and modelling…
Reflection-driven turbulence in the super-Alfvénic solar wind
Romain Meyrand, Jonathan Squire, Alfred Mallet +1
In magnetized, stratified astrophysical environments such as the Sun's corona and solar wind, Alfvénic fluctuations ''reflect'' from background gradients, enabling nonlinear intera…
Electron-ion heating partition in imbalanced solar-wind turbulence
Jonathan Squire, Romain Meyrand, Matthew W. Kunz
A likely candidate mechanism to heat the solar corona and solar wind is low-frequency "Alfvénic" turbulence sourced by magnetic fluctuations near the solar surface. Depending on it…
Mediation of Collisionless Turbulent Dissipation Through Cyclotron Resonance
Trevor A. Bowen, Stuart D. Bale, Benjamin D. G. Chandran +6
The dissipation of magnetized turbulence is fundamental to understanding energy transfer and heating in astrophysical systems. Collisionless interactions, such as resonant wave-par…
On the properties of Alfvénic switchbacks in the expanding solar wind: the influence of the Parker spiral
Jonathan Squire, Zade Johnston, Alfred Mallet +1
Switchbacks -- rapid, large deflections of the solar wind's magnetic field -- have generated significant interest as possible signatures of the key mechanisms that heat the corona…
On the properties of Alfvénic switchbacks in the expanding solar wind: three-dimensional numerical simulations
Zade Johnston, Jonathan Squire, Alfred Mallet +1
Switchbacks -- abrupt reversals of the magnetic field within the solar wind -- have been ubiquitously observed by Parker Solar Probe (PSP). Their origin, whether from processes nea…
The In Situ Signature of Cyclotron Resonant Heating
Trevor A. Bowen, Benjmin D. G. Chandran, Jonathan Squire +9
The dissipation of magnetized turbulence is an important paradigm for describing heating and energy transfer in astrophysical environments such as the solar corona and wind; howeve…
High-frequency heating of the solar wind triggered by low-frequency turbulence
Jonathan Squire, Romain Meyrand, Matthew W. Kunz +3
The fast solar wind's high speeds and nonthermal features require that significant heating occurs well above the Sun's surface. Two leading theories seem incompatible: low-frequenc…
Violation of the zeroth law of turbulence in space plasmas
Romain Meyrand, Jonathan Squire, Alexander A. Schekochihin +1
The zeroth law of turbulence states that, for fixed energy input into large-scale motions, the statistical steady state of a turbulent system is independent of microphysical dissip…
In-situ switchback formation in the expanding solar wind
Jonathan Squire, Benjamin D. G. Chandran, Romain Meyrand
Recent near-sun solar-wind observations from Parker Solar Probe have found a highly dynamic magnetic environment, permeated by abrupt radial-field reversals, or "switchbacks." We s…
[Plasma 2020 Decadal] Disentangling the Spatiotemporal Structure of Turbulence Using Multi-Spacecraft Data
J. M. TenBarge, O. Alexandrova, S. Boldyrev +26
This white paper submitted for 2020 Decadal Assessment of Plasma Science concerns the importance of multi-spacecraft missions to address fundamental questions concerning plasma tur…
Fluidization of collisionless plasma turbulence
Romain Meyrand, Anjor Kanekar, William Dorland +1
In a collisionless, magnetized plasma, particles may stream freely along magnetic-field lines, leading to phase "mixing" of their distribution function and consequently to smoothin…