The Effects of Charge Exchange in a Coupled Thermosphere-Exosphere Model

Hydrogen is produced via the dissociation of compounds in the mesosphere and is transported through the thermosphere to the exobase. In the exosphere, hydrogen becomes a dominant species where its dynamics influence the impact of space weather on Earth. A major process influencing hydrogen in the upper thermosphere and exosphere is charge exchange, which affects both the velocity distribution and density of H. It is one of two primary methods of hydrogen escape from the Earth’s atmosphere. We have previously introduced a novel simulation of neutral dynamics within the thermosphere and exosphere in which each of these two distinct regions influences the other. We now describe the effects of using a plasmasphere model to introduce charge exchange into this two-way coupled model. This work will examine the comparative importance of thermal and non-thermal escape over the solar cycle. It will also examine how density in the thermosphere changes in reaction to the introduction of non-thermal escape mechanisms. Finally, it will examine how charge exchange affects the velocity distribution of hydrogen in the exosphere.