The NCAR-TIEGCM Version 3.0

A new version of the US National Science Foundation National Center for Atmospheric Research (NSF NCAR) thermosphere-ionosphere-electrodynamics general circulation model (TIEGCM) has been developed and released. This paper describes the changes and improvements of the new version (3.0) since its last major release (2.0) in 2016. These include: (a) increasing the model resolution in both the horizontal and vertical dimensions, as well as in the ionospheric dynamo solver; (b) upward extension of the model upper boundary to enable more accurate simulations of the topside ionosphere and neutral density in the lower exosphere; (c) improved parameterization for thermal electron heating rate; (d) resolving transport of minor species N(²D); (e) treating helium as a major species; (f) parameterization for additional physical processes, such as SAPS and electrojet turbulent heating; (g) including parallel ion drag in the neutral momentum equation; (h) nudging of prognostic fields near the lower boundary from external data; (i) modification to the NO reaction rate and auroral heating rate; (j) outputs of diagnostic analysis terms of the equations; (k) new functionalities enabling model simulations of certain recurrent phenomena, such as solar flares and eclipses. We present examples of the model validation during a moderate storm and compare simulation results by turning on/off new functionalities to demonstrate the related new model capabilities. Furthermore, the model was upgraded to comply with the new computer software environment at NSF NCAR for easy installation and run setup and with new visualization tools. Finally, the model limitations and future development plans are discussed.