Abstract:
Some of the linear macroinstabilities which can play important roles in space plasmas like the Earth's ionosphere and magnetosphere are discussed. Starting from the basic concept of plasma instabilities, we proceed to discuss the mathematical tools available for investigating macroinstabilities in plasma. Using equations for the magnetohydrodynamics (MHD), and also two fluids equations where ever necessary, we derive the evolution equations for some macroscopic instabilities and, then, discuss various methods to get the analytical solution for the instabilities. Applications of the instabilities to various phenomena occurring in the ionosphere/magnetosphere are high lighted.