New insights into the complex interplay between drag forces and its thermospheric consequences

Exploiting the coupling of an ionosphere-thermosphere model, it is discovered that ion and viscous drag forces lead to sustained divergent winds, adjustments in mass, modification of pressure gradients, and a redistribution of the radiatively forced thermal energy.

The interplay between the relative magnitudes of the ion and viscous drag forces and its effect on the ionosphere-thermosphere system has not yet been addressed and results in diverse behavior in the neutral wind and temperature structures of the upper atmosphere, dependent upon the type of drag acting on the gas. It is found that viscous drag is more efficient in cooling the dayside thermosphere and heating the nightside than the ion drag force in solar maximum and under quiet geomagnetic activity, resulting in a 150 K day-night temperature difference.