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The GLobal airglOW model, also known as GLOW, is a toolkit of subroutines and driver programs for performing calculations of optical emissions in the upper atmosphere, particularly the thermosphere and ionosphere, above about 100 km altitude. These emissions are caused by combinations of solar-driven photon processes, auroral precipitation, and chemical reactions. GLOW can calculate various spectral features for any combination of solar and/or auroral inputs, given a specification of the neutral atmosphere and the high-altitude ionosphere.
GLOW is designed to work with either theoretical or empirical models of thermospheric neutral densities, or with measured quantities. It is especially configured to use output from the NCAR Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) and Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model (TIME-GCM) (see http://www.hao.ucar.edu/modeling/tgcm/). It is also configured for use with empirical models such as the NRL Mass Spectrometer Incoherent Scatter - 2000 model (NRLMSISE-00) and the International Reference Ionosphere (IRI). GLOW uses modeled or measured solar extreme-ultraviolet spectra and assumed or measured auroral electrons as inputs, and then calculates energetic electron distributions, ionization and excitation rates, the density of ionized and excited species, and the volume emission rates of various emission lines and bands, as a function of altitude and location. Post-processors can then integrate these volume emission rates to calculate column brightness, or perform radiative transfer calculations.
The source code, data files, and basic documentation are available to the research community under the auspices of an open-source academic research license, the terms of which are located at http://download.hao.ucar.edu/pub/stans/glow/Glowlicense.txt. Researchers are encouraged to use the model, report problems, request enhancements, or contribute new elements. For more information, follow the links in the box to the right, or contact Stan Solomon (https://staff.ucar.edu/users/stans).