Quantifying the effect of thermospheric parameterization in a global model

Global climate models have become useful tools for studying the important physical processes that affect the Earth's upper atmosphere. However, the results produced by all models contain uncertainty that stems for the manner in which the model is driven, as well as in the treatment of the internal physics and numerics. In order to fully understand the scientific value of the model results then, it is necessary to have a quantitative understanding of the uncertainty in the model. In this study, the global ionosphere–thermosphere model is used to investigate how uncertainty in the use of parameters in a large scale model can affect the model results. Eight parameters are studied that ultimately have an effect on the thermospheric temperature equation. It is found that among these, uncertainty in the thermal conductivity, NO cooling, and NO binary diffusion coefficients most strongly translate to uncertainty in the temperature and density results. In addition, variations in the eddy diffusion coefficient are shown to result in significant uncertainty in the thermospheric composition, and ultimately the electron density.