الفهرس 
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Abstract
A highly structured plasma environment, with a large number of readily available energy resources, has been revealed by the In Situ measurements in the Martian Ionosphere. The energetic growth in plasma suggests that it is not compatible with the Thermodynamic equilibrium. A wide range of plasma wave characteristics arises due to large deviations from thermodynamic equilibrium. In this way, a large number of wave modes and unstable fluctuations may be sup- ported by the Martian plasma. The main features of fully nonlinearly low-frequency electrostatic wave modes, such as ion acoustic solitary waves and double layer waves in plasmas that are relevant to the Mar- tian Ionosphere will be investigated by this thesis. In order to model ionospheric plasma and study how its variability affects the fundamen- tal features of these waves, this methodology is based upon the use of hydrodynamical modeling as well as observations by Mars Atmosphere and Volatile Evolution (MAVEN). Three chapters are included in this thesis, describing them as follows:
Chapter I, shows a short overview of Mars, where its typical fea- tures and plasma environment are found. Besides, a summary of the major space missions that explored it.
In Chapter II, We investigated how variations in number density in plasma affect the propagation of low-frequency electrostatic waves in the planet’s ionosphere. We use a collisionless inhomogeneous un- magnetized plasma model with two positive cold ion species (O+, H+) with nonthermal electrons for this purpose. the basic equations are reduced to one evolution equation. The latter has been analyzed and solved numerically to obtain an arbitrary amplitude shock wave pro- file as well as the possible regions for the existing waves. We’ve put forward a negative potential, which is consistent with the compressive wave profile. An interpretation of the electrostatic waves, which can be found in Mars’ ionizing atmosphere, is based on findings from this investigation. We’re going to be able to explain how the gas is lost from the ionosphere if we can observe this wave in Mars’ Ionosphere.
In Chapter III, We investigated the propagation properties of fully
nonlinear ion-acoustic solitary waves and double-layer waves in the Martian ionosphere. The plasma model consists of three positive ions (H+, O+, and O+) and superthermal electron distribution. Sagdeev pseudo-potential is obtained for arbitrary amplitude ion-acoustic waves. The effects of plasma parameters on the nature of the solitary waves and double layer waves are investigated. The velocity of the wave phase has been established to be supersonic, and this is in agreement with the observations.