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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…
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…
Tripolar guide magnetic fields due to island coalescence in solar wind current sheets: Simulation and theory
Newman, David L.; Eriksson, Stefan; Lapenta, Giovanni
Reconnecting current sheets (CSs) in the solar wind near 1 AU have been previously identified that exhibit a modified Hall magnetic field perturbation of the nominal guide field characterized by a "tripolar" structure with depressions on both sides of a central maximum [Eriksson et al., Astrophys. J. 805, 43 (2015)]. Such CSs were inferred to cont…
Turbulence in space plasmas: Who needs it?
Matthaeus, W. H.
The complex nonlinear dynamical phenomenon described as turbulence, is known to have a great impact on fluids, magnetohydrodynamic systems, and on plasmas. This paper reviews selected topics on turbulence in these systems, emphasizing the multiscale space-time properties of the turbulence cascade as it transfers energy from large scale reservoirs,…
Cold ion energization at separatrices during magnetic reconnection
Divin, A.; Deca, J.; Markidis, S. +5 more
Separatrices of magnetic reconnection host intense perpendicular Hall electric fields. The fields are produced by the decoupling of the ion and electron components and are associated with the in-plane electrostatic potential drop between the inflow and outflow regions. The width of these structures is typically less than the ion inertial length, w…
Interaction of electron acoustic waves in the presence of superthermal electrons in terrestrial magnetosphere
Masood, W.; Jahangir, R.
We have investigated the propagation and interaction of nonlinear electron acoustic waves (EAWs) in a plasma comprising hot (superthermal) and cold electrons and immobile ions. We have derived the Korteweg-de Vries equation for EAWs in the small amplitude limit. Employing the Hirota's Direct method, we have investigated the multisoliton solutions …
Reconnection from a turbulence perspective
Eastwood, J. P.; Matthaeus, W. H.; Stawarz, J. E. +6 more
The spectral properties associated with laminar, anti-parallel reconnection are examined using a 2.5D kinetic particle in cell simulation. Both the reconnection rate and the energy spectrum exhibit three distinct phases: an initiation phase where the reconnection rate grows, a quasi-steady phase, and a declining phase where both the reconnection r…
Overtaking collisions of double layers and solitons: Tripolar structures and dynamical polarity switches
Olivier, C. P.; Verheest, F.
Overtaking collisions between double layers and solitons are investigated through the numerical simulation of the Gardner equation that governs small-amplitude double layers. The results show that the double layer emerges unaffected after the completion of the collision. However, the soliton that emerges from the collision has the opposite polarit…
Resonant instabilities of kinetic Alfvén waves in the Earth's magnetosphere with superthermal electrons
Lakhina, G. S.; Singh, S. V.; Barik, K. C.
A theoretical plasma model for the generation of kinetic Alfvén waves (KAWs), having background Maxwellian ions, κ-electrons, and drifting Maxwellian beam ions, is discussed. The ion beam streams along the ambient magnetic field, whereas velocity shear is perpendicular to it. The role played by nonthermal electrons in the excitation of resonant KA…
Generation of kinetic Alfvén waves in dayside magnetopause reconnection: A 3-D global-scale hybrid simulation
Wang, Xueyi; Lin, Yu; Guo, Zhifang +1 more
In this paper, we perform a three-dimensional (3-D) global-scale hybrid simulation to investigate the generation of kinetic Alfvén waves (KAWs) in reconnection at the dayside magnetopause. In the simulation, the magnetopause reconnection takes place due to a self-consistent interaction between the solar wind and Earth's magnetosphere, in which the…