The effects of suprathermal particles on the existence domain of oblique low-frequency solitary waves in multi-component magnetospheric plasmas

2021 ◽  
Vol 28 (5) ◽  
pp. 052901
Author(s):  
O. R. Rufai ◽  
R. Bharuthram ◽  
S. K. Maharaj
Keyword(s):  
Solitary Waves ◽  
Low Frequency ◽  
Existence Domain ◽  
Suprathermal Particles

scholarly journals Comparative study of dust acoustic solitons in two-temperature ion homogeneous and inhomogeneous plasmas

2020 ◽  
Vol 14 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Rashmi Srivastava ◽  
Hitendra K. Malik ◽  
Devi Singh
Keyword(s):  
Solitary Waves ◽  
Inhomogeneous Plasma ◽  
Low Frequency ◽  
Soliton Solutions ◽  
Dusty Plasmas ◽  
Number Density ◽  
Dust Charge ◽  
Plasma Species ◽  
Dust Acoustic ◽  
Two Temperature

AbstractThe dust acoustic solitary waves are theoretically investigated in dusty plasmas for different cases of with and without density gradients. These low-frequency solitary waves are studied using appropriate Korteweg–de Vries equations obtained using relevant stretched coordinates. The soliton solutions in homogeneous plasma, weakly inhomogeneous plasma and strongly inhomogeneous plasma, are thoroughly investigated for studying the effect of different parameters like dust charge and density of all the plasma species on the soliton profiles. The combination of the dust charge with its number density changes the dynamics of the solitons and that is further affected by the number density of the hot ion with respect to the cold ions.

Low Frequency Solitary Waves in Magnetized Electron–Positron–Ion Plasmas

2005 ◽  
Vol 22 (3) ◽  
pp. 632-635 ◽  
Author(s):  
M. Ansar Mahmood ◽  
S Mahmood ◽  
Arshad M Mirza ◽  
H Saleem
Keyword(s):  
Solitary Waves ◽  
Low Frequency ◽  
Electron Positron

Nonlinear low-frequency waves in dusty self-gravitating plasmas

2000 ◽  
Vol 64 (4) ◽  
pp. 359-370 ◽  
Author(s):  
VICTORIA V. YAROSHENKO ◽  
FRANK VERHEEST
Keyword(s):  
Solitary Waves ◽  
Modulational Instability ◽  
Low Frequency ◽  
Nonlinear Effects ◽  
Dusty Plasmas ◽  
Short Wave ◽  
Electrostatic Waves ◽  
Significant Difference ◽  
Dust Acoustic ◽  
Limiting Case

Nonlinear electrostatic waves in self-gravitating dusty plasmas are considered in two limiting cases, according to whether the charged-particle dynamics is governed mostly by electrostatic forces or mostly by gravitation. This shows a significant difference between these two plasma media with respect to the envelope dynamics in the nonlinear regime. In the former case, when ω2pα > ω2Jα, the amplitude perturbations are longitudinally unstable only in the short-wave range, and the nonlinear effects can result in the formation of longitudinal dust-acoustic solitary waves. But even weak self-gravitational effects can lead to the existence of a long-wavelength range, where self-gravitation prevents the formation of dust-acoustic solitons, and only transverse solitary structures are possible. In the other limiting case (ω2pα < ω2Jα), there is always a transverse modulational instability, which can lead to transverse solitary waves. In both cases, there is a threshold for solitary-wave formation.

Fully nonlinear periodic internal waves in a two-fluid system of finite depth

2010 ◽  
Vol 652 ◽  
pp. 259-298 ◽  
Author(s):  
R. CAMASSA ◽  
P.-O. RUSÅS ◽  
A. SAXENA ◽  
R. TIRON
Keyword(s):  
Closed Form ◽  
Internal Waves ◽  
Solitary Waves ◽  
Travelling Wave ◽  
Euler System ◽  
Layer System ◽  
Fluid System ◽  
Model Solutions ◽  
Existence Domain ◽  
Two Fluid

Periodic travelling wave solutions for a strongly nonlinear model of long internal wave propagation in a two-fluid system are derived and extensively analysed, with the aim of providing structure to the rich parametric space of existence of such waves for the parent Euler system. The waves propagate at the interface between two homogeneous-density incompressible fluids filling the two-dimensional domain between rigid planar boundaries. The class of waves with a prescribed mean elevation, chosen to coincide with the origin of the vertical (parallel to gravity) axis, and prescribed zero period-average momentum and volume-flux is studied in detail. The constraints are selected because of their physical interpretation in terms of possible processes of wave generation in wave-tanks, and give rise to a quadrature formula which is analysed in parameter space with a combination of numerical and analytical tools. The resulting model solutions are validated against those computed numerically from the parent Euler two-layer system with a boundary element method. The parametric domain of existence of model periodic waves is determined in closed form by curves in the amplitude–speed (A, c) parameter plane corresponding to infinite period limiting cases of fronts (conjugate states) and solitary waves. It is found that the existence domain of Euler solutions is a subset of that of the model. A third closed form relation between c and A indicates where the Euler solutions cease to exist within the model's domain, and this is related to appearance of ‘overhanging’ (multiple valued) wave profiles. The model existence domain is further partitioned in regions where the model is expected to provide accurate approximations to Euler solutions based on analytical estimates from the quadrature. The resulting predictions are found to be in good agreement with the numerical Euler solutions, as exhibited by several wave properties, including kinetic and potential energy, over a broad range of parameter values, extending to the limiting cases of critical depth ratio and extreme density ratios. In particular, when the period is sufficiently long, model solutions show that for a given supercritical speed waves of substantially larger amplitude than the limiting amplitude of solitary waves can exist, and are good approximations of the corresponding Euler solutions. This finding can be relevant for modelling field observations of oceanic internal waves, which often occur in wavetrains with multiple peaks.

scholarly journals TSUNAMI RUNUP AMPLIFICATION OF BREAKING AND NON-BREAKING ERROR-FUNCTION WAVES OVER A SLOPING BEACH IN SHADOW ZONE BY A SMALL ISLAND

2020 ◽  
pp. 13
Author(s):  
Sunghoon Han ◽  
James Kaihatu ◽  
Patrick Lynett ◽  
Costas Synolakis
Keyword(s):  
Solitary Waves ◽  
Error Function ◽  
Low Frequency ◽  
Peak Frequency ◽  
Small Island ◽  
Shadow Zone ◽  
Free Surface Elevation ◽  
Linear Superposition ◽  
Time Frequency ◽  
Sloping Beach

The time series of free surface elevation measured in and outside the shadow zone were compared and analyzed in the time-frequency domain by employing the continuous wavelet transform. Regardless of the conditions of the ERF wave in the shadow zone, an increase in magnitude of energy is noticeable not only in the peak frequency within a range of approximately 0.8 to 1 Hz but also in the low-frequency range of around 0.1 Hz corresponding to second up to third crest of the leading wave. To determine the effective frequency of ERF waves and evaluate their runup characteristics, we applied a new method of describing the ERF wave, which consists of linear superposition of two solitary waves. As a result, the ERF waves show the same trend in runup characteristics as for solitary waves.

scholarly journals Lower-hybrid (LH) oscillitons evolved from ion-acoustic (IA)/ion-cyclotron (IC) solitary waves: effect of electron inertia

2010 ◽  
Vol 17 (3) ◽  
pp. 245-268 ◽  
Author(s):  
J. Z. G. Ma ◽  
A. Hirose
Keyword(s):  
Solitary Waves ◽  
Power Spectra ◽  
Low Frequency ◽  
Lower Hybrid ◽  
Electron Inertia ◽  
Background Density ◽  
Ion Acoustic ◽  
Ion Cyclotron ◽  
Cartesian Geometry ◽  
General Dispersion

Abstract. Lower-hybrid (LH) oscillitons reveal one aspect of geocomplexities. They have been observed by rockets and satellites in various regions in geospace. They are extraordinary solitary waves the envelop of which has a relatively longer period, while the amplitude is modulated violently by embedded oscillations of much shorter periods. We employ a two-fluid (electron-ion) slab model in a Cartesian geometry to expose the excitation of LH oscillitons. Relying on a set of self-similar equations, we first produce, as a reference, the well-known three shapes (sinusoidal, sawtooth, and spiky or bipolar) of parallel-propagating ion-acoustic (IA) solitary structures in the absence of electron inertia, along with their Fast Fourier Transform (FFT) power spectra. The study is then expanded to illustrate distorted structures of the IA modes by taking into account all the three components of variables. In this case, the ion-cyclotron (IC) mode comes into play. Furthermore, the electron inertia is incorporated in the equations. It is found that the inertia modulates the coupled IA/IC envelops to produce LH oscillitons. The newly excited structures are characterized by a normal low-frequency IC solitary envelop embedded by high-frequency, small-amplitude LH oscillations which are superimposed upon by higher-frequency but smaller-amplitude IA ingredients. The oscillitons are shown to be sensitive to several input parameters (e.g., the Mach number, the electron-ion mass/temperature ratios, and the electron thermal speed). Interestingly, whenever a LH oscilliton is triggered, there occurs a density cavity the depth of which can reach up to 20% of the background density, along with density humps on both sides of the cavity. Unexpectedly, a mode at much lower frequencies is also found beyond the IC band. Future studies are finally highlighted. The appendices give a general dispersion relation and specific ones of linear modes relevant to all the nonlinear modes encountered in the text.

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