Search Publications
Stability and instability of Langmuir waves via active subspace decompositions
Mattingly, G.; Longaker, B.; Palmer, N. +2 more
We study the stability and instability of Langmuir waves propagating in a hot, unmagnetized plasma modeled by the Vlasov–Poisson system and encompassing a variety of velocity distributions, including perturbations of Lorentzian, Kappa, and incomplete Maxwellian steady states. The influence of both high-frequency spatial perturbations and physical …
Alfvénic fluctuations in the expanding solar wind: Formation and radial evolution of spherical polarization
Hellinger, P.; Matteini, L.; Horbury, T. S. +7 more
We investigate properties of large-scale solar wind Alfvénic fluctuations and their evolution during radial expansion. We assume a strictly radial background magnetic field B ∥ R, and we use two-dimensional hybrid (fluid electrons, kinetic ions) simulations of balanced Alfvénic turbulence in the plane orthogonal to B; the simulated plasma evolves …
Kinetic numerical scaling of Alfven cyclotron instability in non-thermal solar wind plasmas
Shahzad, Muhammad Ahsan; Aman-ur-Rehman; Bilal, Muhammad +3 more
Linear plasma kinetic theory for a non-thermal, magnetized, homogeneous, and collisionless plasma is incorporated to study Alfvén cyclotron instability (ACI) driven by the ion/proton perpendicular temperature anisotropy (T⊥p/T∥p>1) ( ⊥, ∥ symbols designate directions perpendicular and parallel to ambient magnetic field, respectively), and the w…
Role of nonlinear structures and associated turbulence generation dayside magnetosphere reconnection sites
Sharma, R. P.; Pathak, Neha; Sharma, Suresh C. +1 more
A numerical simulation is implemented to investigate the role of whistler wave in the presence of the ponderomotive force-driven density modification and the magnetic field perturbation due to preexisting magnetic islands. The dynamical equation governing the whistler waves is derived and solved using numerical methods to assess their role. The si…
Slow wind belt in the quiet solar corona
Romoli, M.; Andretta, V.; Uslenghi, M. +16 more
The slow solar wind belt in the quiet corona, observed with the Metis coronagraph on board Solar Orbiter on May 15, 2020, during the activity minimum of the cycle 24, in a field of view extending from 3.8 R ⊙ to 7.0 R ⊙, is formed by a slow and dense wind stream running along the coronal current sheet, accelerating in the radial direction and reac…
Energy transfer of the solar wind turbulence based on Parker solar probe and other spacecraft observations
He, Jiansen; Wang, Xin; Tu, Chuanyi +2 more
The supersonic solar wind, first predicted by Parker and then observed by Mariners, extends to form a heliosphere around the Sun. The energy supply from the energy containing range, the energy cascade though the inertial range, and the eventual energy dissipation are three basic processes of the energy transfer in the solar wind and have been stud…
Unexpected energetic particle observations near the Sun by Parker Solar Probe and Solar Orbiter
McComas, D. J.; Rodríguez-Pacheco, J.; Wimmer-Schweingruber, R. F. +6 more
Solar energetic particles (SEPs) from suprathermal (few keV) up to relativistic (∼few GeV) energies are accelerated at the Sun in association with solar flares and coronal mass ejection-driven shock waves. Although our knowledge of the origin, acceleration, and transport of these particles from close to the Sun through the interplanetary medium ha…
The electric fields and "lightning jets" of the Sun and solar wind
Driscoll, C. F.
A model of electric energization of the solar wind and corona is developed, including electro-magnetic particle effects precluded by traditional magneto-hydro (MHD) assumptions. Using standard 1D radial solar models for particle density and temperature, the core gravito-electric field is calculated; and the range of possible photospheric photo-ele…
Kinetic study of ion acoustic waves in Venusian ionosphere
Lakhina, G. S.; Kamalam, T.; Singh, S. V. +1 more
Kinetic dispersion of the ion acoustic waves has been explored for an unmagnetized five component plasma system comprising of Venusian protons, Venusian oxygen ions, Venusian electrons, solar wind protons, and kappa electrons. The solar wind protons and electrons are assumed to be streaming along the ambient magnetic field. The plasma parameters f…
Investigation of the homogeneity of energy conversion processes at dipolarization fronts from MMS measurements
Russell, C. T.; Lavraud, B.; Anderson, B. J. +28 more
We report on six dipolarization fronts (DFs) embedded in fast earthward flows detected by the Magnetospheric Multiscale mission during a substorm event on 23 July 2017. We analyzed Ohm's law for each event and found that ions are mostly decoupled from the magnetic field by Hall fields. However, the electron pressure gradient term is also contribut…