scholarly journals Large amplitude inertial compressional Alfvénic shock and solitary waves, and acceleration of ions in magnetohydrodynamic plasmas

2013 ◽  
Vol 20 (5) ◽  
pp. 052103 ◽  
Author(s):  
Anuraj Panwar ◽  
H. Rizvi ◽  
C. M. Ryu
Keyword(s):  
Solitary Waves ◽  
Large Amplitude ◽  
Magnetohydrodynamic Plasmas

Effects of ion and electron drifts on large amplitude solitary waves in a relativistic plasma

1997 ◽  
Vol 4 (12) ◽  
pp. 4232-4235 ◽  
Author(s):  
Rajkumar Roychoudhury ◽  
S. K. Venkatesan ◽  
Chandra Das
Keyword(s):  
Solitary Waves ◽  
Large Amplitude ◽  
Relativistic Plasma

scholarly journals Large-amplitude solitary waves in finite temperature dusty plasma

1997 ◽  
Vol 4 (6) ◽  
pp. 2305-2306 ◽  
Author(s):  
R. Roychoudhury ◽  
Soma Mukherjee
Keyword(s):  
Dusty Plasma ◽  
Solitary Waves ◽  
Finite Temperature ◽  
Large Amplitude

scholarly journals Anomalous width variation of rarefactive ion acoustic solitary waves in the context of auroral plasmas

2004 ◽  
Vol 11 (2) ◽  
pp. 219-228 ◽  
Author(s):  
S. S. Ghosh ◽  
G. S. Lakhina
Keyword(s):  
Solitary Waves ◽  
Nonlinear Theory ◽  
Acoustic Waves ◽  
Large Amplitude ◽  
Magnetized Plasma ◽  
Amplitude Variation ◽  
Fully Nonlinear ◽  
Weakly Nonlinear ◽  
Ion Acoustic Solitary Waves ◽  
Ion Acoustic

Abstract. The presence of dynamic, large amplitude solitary waves in the auroral regions of space is well known. Since their velocities are of the order of the ion acoustic speed, they may well be considered as being generated from the nonlinear evolution of ion acoustic waves. However, they do not show the expected width-amplitude correlation for K-dV solitons. Recent POLAR observations have actually revealed that the low altitude rarefactive ion acoustic solitary waves are associated with an increase in the width with increasing amplitude. This indicates that a weakly nonlinear theory is not appropriate to describe the solitary structures in the auroral regions. In the present work, a fully nonlinear analysis based on Sagdeev pseudopotential technique has been adopted for both parallel and oblique propagation of rarefactive solitary waves in a two electron temperature multi-ion plasma. The large amplitude solutions have consistently shown an increase in the width with increasing amplitude. The width-amplitude variation profile of obliquely propagating rarefactive solitary waves in a magnetized plasma have been compared with the recent POLAR observations. The width-amplitude variation pattern is found to fit well with the analytical results. It indicates that a fully nonlinear theory of ion acoustic solitary waves may well explain the observed anomalous width variations of large amplitude structures in the auroral region.

scholarly journals Optimal transient growth in thin-interface internal solitary waves

2018 ◽  
Vol 840 ◽  
pp. 342-378 ◽  
Author(s):  
Pierre-Yves Passaggia ◽  
Karl R. Helfrich ◽  
Brian L. White
Keyword(s):  
Solitary Waves ◽  
Carrier Frequency ◽  
Large Amplitude ◽  
Stokes Equations ◽  
Normal Growth ◽  
Energy Gain ◽  
Wkb Approximation ◽  
Internal Solitary Waves ◽  
Transient Growth ◽  
Optimal Disturbances

The dynamics of perturbations to large-amplitude internal solitary waves (ISWs) in two-layered flows with thin interfaces is analysed by means of linear optimal transient growth methods. Optimal perturbations are computed through direct–adjoint iterations of the Navier–Stokes equations linearized around inviscid, steady ISWs obtained from the Dubreil-Jacotin–Long (DJL) equation. Optimal perturbations are found as a function of the ISW phase velocity $c$ (alternatively amplitude) for one representative stratification. These disturbances are found to be localized wave-like packets that originate just upstream of the ISW self-induced zone (for large enough $c$) of potentially unstable Richardson number, $Ri<0.25$. They propagate through the base wave as coherent packets whose total energy gain increases rapidly with $c$. The optimal disturbances are also shown to be relevant to DJL solitary waves that have been modified by viscosity representative of laboratory experiments. The optimal disturbances are compared to the local Wentzel–Kramers–Brillouin (WKB) approximation for spatially growing Kelvin–Helmholtz (K–H) waves through the $Ri<0.25$ zone. The WKB approach is able to capture properties (e.g. carrier frequency, wavenumber and energy gain) of the optimal disturbances except for an initial phase of non-normal growth due to the Orr mechanism. The non-normal growth can be a substantial portion of the total gain, especially for ISWs that are weakly unstable to K–H waves. The linear evolution of Gaussian packets of linear free waves with the same carrier frequency as the optimal disturbances is shown to result in less energy gain than found for either the optimal perturbations or the WKB approximation due to non-normal effects that cause absorption of disturbance energy into the leading face of the wave. Two-dimensional numerical calculations of the nonlinear evolution of optimal disturbance packets leads to the generation of large-amplitude K–H billows that can emerge on the leading face of the wave and that break down into turbulence in the lee of the wave. The nonlinear calculations are used to derive a slowly varying model of ISW decay due to repeated encounters with optimal or free wave packets. Field observations of unstable ISW by Moum et al. (J. Phys. Oceanogr., vol. 33 (10), 2003, pp. 2093–2112) are consistent with excitation by optimal disturbances.

scholarly journals Mass and momentum transfer by solitary internal waves in a shelf zone

2012 ◽  
Vol 19 (2) ◽  
pp. 265-272 ◽  
Author(s):  
N. Gavrilov ◽  
V. Liapidevskii ◽  
K. Gavrilova
Keyword(s):  
Mathematical Model ◽  
Internal Waves ◽  
Solitary Waves ◽  
Large Amplitude ◽  
Shelf Zone ◽  
Swash Zone ◽  
Second Mode ◽  
Before And After ◽  
The Mathematical Model ◽  
Solitary Internal Waves

Abstract. The evolution of large amplitude internal waves propagating towards the shore and more specifically the run up phase over the "swash" zone is considered. The mathematical model describing the generation, interaction, and decaying of solitary internal waves of the second mode in the interlayer is proposed. The exact solution specifying the shape of solitary waves symmetric with respect to the unperturbed interface is constructed. It is shown that, taking into account the friction on interfaces in the mathematical model, it is possible to describe adequately the change in the phase and amplitude characteristics of two solitary waves moving towards each other before and after their interaction. It is demonstrated that propagation of large amplitude solitary internal waves of depression over a shelf could be simulated in laboratory experiments by internal symmetric solitary waves of the second mode.

scholarly journals Propagation of ion-acoustic solitary waves in a relativistic electron-positron-ion plasma

2011 ◽  
Vol 89 (3) ◽  
pp. 299-309 ◽  
Author(s):  
E. Saberian ◽  
A. Esfandyari-Kalejahi ◽  
M. Akbari-Moghanjoughi
Keyword(s):  
Solitary Wave ◽  
Relativistic Electron ◽  
Solitary Waves ◽  
Thermal Energy ◽  
Large Amplitude ◽  
Considerable Effect ◽  
Potential Well ◽  
Electron Positron ◽  
Ion Acoustic Solitary Waves ◽  
Ion Acoustic

The propagation of large amplitude ion-acoustic solitary waves (IASWs) in a fully relativistic plasma consisting of cold ions and ultra-relativistic hot electrons and positrons is investigated using the Sagdeev pseudopotential method in a relativistic hydrodynamics model. The effects of streaming speed of the plasma fluid, thermal energy, positron density, and positron temperature on large amplitude IASWs are studied by analysis of the pseudopotential structure. It is found that in regions in which the streaming speed of the plasma fluid is larger than that of the solitary wave, by increasing the streaming speed of the plasma fluid, the depth and width of the potential well increase, resulting in narrower solitons with larger amplitude. This behavior is opposite to the case where the streaming speed of the plasma fluid is less than that of the solitary wave. On the other hand, an increase in the thermal energy results in wider solitons with smaller amplitude, because the depth and width of the potential well decrease in that case. Additionally, the maximum soliton amplitude increases and the width becomes narrower as a result of an increase in positron density. It is shown that varying the positron temperature does not have a considerable effect on the width and amplitude of IASWs. The existence of stationary soliton-like arbitary amplitude waves is also predicted in fully relativistic electron-positron-ion (EPI) plasmas. The effects of streaming speed of the plasma fluid, thermal energy, positron density, and positron temperature on these kinds of solitons are the same for large amplitude IASWs.

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