High-latitude Energy and Momentum Balance in the Lower Thermosphere

The high-latitude lower thermosphere is significantly influenced by energy and momentum forcing associated with magnetosphere-ionosphere coupling. Electric currents produce a force on the air and dissipate energy through Joule heating. The precipitation of energetic electrons and ions into the auroral regions produces additional direct heating, and also influences the energy balance through production of stored chemical energy, through modification of the concentrations of radiatively active species, and through modification of the electrical conductivity. We examine the resulting energy and momentum balance of the lower thermosphere with the aid of a thermosphere-ionosphere-electrodynamics general circulation model.