Methods for ‘ An unexpected cooling effect in Saturn ’ s polar upper atmosphere ’

The thermosphere model is a global three-dimensional time-dependent general circulation model. The details of the model have been described by Ref 4. We will limit our discussion here to features unique to this study, and general points that will be useful in the discussion that follows. First we describe the symmetry assumptions, boundary conditions and physical parameters of the model, before moving on to briefly describe the calculations that it performs.