Challenges to understanding the Earth's ionosphere and thermosphere

The I-T is strongly influenced by wave motions of the neutral atmosphere from the lower atmosphere and is coupled to the magnetosphere, which supplies energetic particle precipitation and field-aligned currents at high latitudes. The resulting plasma dynamics are associated with currents generated by solar heating and upward propagating waves, by heating from energetic particles and electromagnetic energy from the magnetosphere and by the closure of the field-aligned currents applied at high latitudes.

These three contributors to the current are functions of position, magnetic activity, and other variables that must be unraveled to understand how the I-T responds to coupling from the surrounding regions of geospace. We have captured the challenges to this understanding in four major themes associated with coupling to the lower atmosphere, the generation and flow of currents within the I-T region, the coupling to the magnetosphere, and the response of the I-T region reflected in the neutral and plasma density changes.