چكيده به لاتين
Satellite observations have confirmed the presence of depletion density electrostatic solitons in the ionosphere layers. According to research, these structures are probably caused by non - thermal (non-maxwellian) electrons and ion sheared flow. In addition, the presence of the magnetic field also caused changes in these structures. Freja observations indicate the presence of electrostatic solitary structures with density depletions, However, satellites havenot confirmed the existence of the cairns distribution function for electrons in ionosphere but this function has explaned the formation of nonlinear structures with density depletion. It is found theorically and confirmed experimentally that only positive solitons exist in two components plasma and it has been reported by several authors that it is possible to obtain both compressive and rarefactive solitons in plasma with more than two components. In this dissertation, we review the effects of ion temperature on the formation of instability and solitary structures in ionospheric plasma. First, we examine soliton structures at altitudes 600 km and 1000 km in the auroral region and ion tempratur effects on soliton structures in nonthermal plasma consisting of adiabatic warm ions and nonthermal electrons, then we review results of researchers work about effects of ion temperature, of critical Mach number, angle of obliqueness and magnetic field on the solitons amplitude, coexistence of rarefactive and compressive solitons, shapes of solitons and solitons width in ionospheric plasma. we have investigated effects of ion temperature on the nonlinear structures in ionospheric plasma. furthermore, we hve investigated effects of critical Mach number, angle of obliqueness and magnetic field on the solitons amplitude, coexistence of rarefactive and compressive solitons, shapes of solitons and solitons width in ionospheric plasma. behavior of acoustic ion waves is described by fluid equations. Kdv equation was solved for compressive and rarefactive soliton waves in limit of small amplitude in fully ionized, collisionless and magnetized plasma.
