Magentospheric Plasmas

Aperiodic magnetospheric oscillations

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In this work, we have modeled the aperiodic electrostatic oscillations in the magnetopause region in the earth's magneticphere. Here, we have combined both the electron and ion fluids, using a single fluid Hall-MHD model where the perturbation is considered to be electromagnetic which is of a slower timescale, in the magnetospheric regime.

Here, we have used a generalised polybaric pressure equations to describe the fluid dynamics. In this case, the soliton solution is obtained solely from the variation of the magnetic field given by two partial differential equations known as the structure equations, which describes the flow of plasma.

Murchana Khusroo and Madhurjya P Bora, Physical Review E 99, 013205 (2019)

Solitary structures with thermal anisotropy

Temperature anisotropy is one of the primary physical effects that we consider in this work where the evolution of nonlinear waves in plasmas is considered.

We have considered here an electrostatic perturbation in a slow timescale, in the auroral plasma, where the electrons are primarily expressed as Boltzmannian. This signifies that even if the plasma acts like a neutral gas, the Debye screening ensures that the long range Coulomb interaction mediates the perturbation. Owing to the slowness of the time scale, the ions behave as anisotropic and are treated with the help of the CGL equations and the electrons are governed by a bi-Maxwellian distribution function.

M Khusroo and MP Bora, Plasma Physics & Controlled Fusion 57, 115005 (2015).