a region of relatively dense but cool plasma, surrounding Earth, extending to distances of about 5 Earth radii (RE). The plasmasphere is the upward extension of the Earth's ionosphere, getting less and less dense with increasing distance, and it shares the Earth's rotation.

The region of the atmosphere consisting of cold dense plasma originating in the ionosphere and trapped by the Earth's magnetic field.

A region of the inner magnetosphere that contains relatively cool (low energy) and dense plasma. This area can be considered an outer extension of the ionosphere.

The region of the magnetosphere in which the plasma (composed of electrons and positive ions) rotates with the earth. Beyond the plasmapause, magnetospheric convection driven by the interaction of the solar wind with the outer magnetosphere dominates the motion.

The plasmasphere, or inner magnetosphere is a region of the Earth's magnetosphere consisting of low energy (cool) plasma. It is located above the ionosphere. The outer boundary of the plasmasphere is known as the plasmapause, which is defined by an order of magnitude drop in plasma density.