The Thermospheric General Circulation Models (TGCM's)

Sample Plots from TIEGCM v1.95 Benchmark Runs



Introduction

The High Altitude Observatory at the National Center for Atmospheric Research has developed a series of numeric simulation models of the Earth's upper atmosphere, including the upper Stratosphere, Mesosphere, and Thermosphere. The Thermospheric General Circulation Models (TGCM's) are three-dimensional, time-dependent models of the EARTH's neutral upper atmosphere. The models use a finite differencing technique to obtain a self-consistent solution for the coupled, nonlinear equations of hydrodynamics, thermodynamics, continuity of the neutral gas and for the coupling between the dynamics and the composition.

Recent models in the series include a self-consistent aeronomic scheme for the coupled Thermosphere/Ionosphere system, the Thermosphere Ionosphere Electrodynamic General Circulation Model (TIEGCM), and an extension of the lower boundary from 97 to 30 km, including the physical and chemical processes appropriate for the Mesosphere and upper Stratosphere, the Thermosphere Ionosphere Mesosphere Electrodynamic General Circulation Model (TIME-GCM). A global mean, or column model, has also been developed in parallel with the TGCM's. The global mean model is used as a time-dependent, one-dimensional platform from which new chemical, dynamic and numeric schemes are developed and tested before being introduced into the 3-d GCM's.

For an introduction to the TIEGCM Community Model, and several examples of upper atmosphere research using this model, please see Astrid Maute's presentation to students at the 2013 CEDAR Workshop

Announcements

Documentation

  • User's Guide (updated June, 2013): [html] [pdf]
  • TIEGCM Model Description [pdf]
  • Cheat-Sheet for HSI interface to the NCAR HPSS [html]
  • CISL Frequently Used Commands within HSI session [pdf]
  • CISL HPSS usage page [html]
  • TIEGCM Code Structure Flowchart (Documentation section of the Download page): [15-page pdf]
  • TIEGCM Code Structure Flowchart (Documentation section of the Download page): [single-page pdf]

Simulations

References:

The TIE-GCM and related models are developed at the NCAR High Altitude Observatory by Ray Roble and colleagues, with support from the National Science Foundation and NASA. Some of the primary references are given below.

  • Dickinson, R. E., E. C. Ridley and R. G. Roble, A three-dimensional general circulation model of the thermosphere, J. Geophys. Res., 86, 1499-1512, 1981.
  • Dickinson, R. E., E. C. Ridley and R. G. Roble, Thermospheric general circulation with coupled dynamics and composition, J. Atmos. Sci., 41, 205-219, 1984.
  • Roble, R. G., and E. C. Ridley, An auroral model for the NCAR thermospheric general circulation model (TGCM), Annales Geophys., 5A, 369-382, 1987.
  • Roble, R. G., E. C. Ridley and R. E. Dickinson, On the global mean structure of the thermosphere, J. Geophys. Res., 92, 8745-8758, 1987.
  • Roble, R. G., E. C. Ridley, A. D. Richmond and R. E. Dickinson, A coupled thermosphere/ionosphere general circulation model, Geophys. Res. Lett., 15, 1325-1328, 1988.
  • Richmond, A. D., E. C. Ridley and R. G. Roble, A Thermosphere/Ionosphere General Circulation Model with coupled electrodynamics, Geophys. Res. Lett., 19, 601-604, 1992.
  • Roble, R. G., and E. C. Ridley, A thermosphere-ionosphere-mesosphere-electrodynamics general circulation model (TIME-GCM): equinox solar cycle minimum simulations (30-500 km), Geophys. Res. Lett., 21, 417-420, 1994.
  • Roble, R. G., Energetics of the mesosphere and thermosphere, AGU, Geophysical Monographs, eds. R. M. Johnson and T. L. Killeen, 87, 1-22, 1995.
  • Wang, W., M. Wiltberger, A. G. Burns, S. Solomon, T. L. Killeen, N. Maruyama, and J. Lyon, Initial results from the CISM coupled magnetosphere-ionosphere-thermosphere (CMIT) model: thermosphere ionosphere responses, J. Atmos. Sol.-Terr. Phys., 66, 1425-1442, doi:10.1016/j.jastp.2004.04.008, 2004.
  • Solomon, S. C., and L. Y. Qian, Solar extreme-ultraviolet irradiance for general circulation models, J. Geophys. Res., 110, A10306, doi:10.1029/2005JA011160, 2005.
  • Qian, L., A. G. Burns, B. A. Emery, B. Foster, G. Lu, A. Maute, A. D. Richmond, R. G. Roble, S. C. Solomon, and W. Wangm, The NCAR TIE-GCM: A community model of the coupled thermosphere/ionosphere system, in Modeling the Ionosphere-Thermosphere System, AGU Geophysical Monograph Series, 2014.