this fixed boundary condition is not necessarily unique. @Akgun2018a showed that for sufficiently large magnetospheric twists, there exist degeneracies, i.e. different solutions of the GSE for the same boundary conditions (the same set of four parameters). These solutions differ in their energy, twist and the radial extent of the toroidal currents.

Table \[tab:model\_overview\] shows the parameters used to construct the initial data for our numerical simulations. Each of the series A, B and C of initial models were chosen to have identical parameters but [*different*]{} magnetospheric energies and, hence, represent degenerate magnetospheric models. We would like to point out that the value of ${P_{\rm c}}$ is only equal, within each series, up to the second significant digit, due to numerical reasons. Figure \[fig:initial\_model\] shows the energy of the initial models as a function of the parameter ${P_{\rm c}}$. Models within each spiral curve (constant $s$ and $\sigma$) and with the same value of ${P_{\rm c}}$ have identical boundary conditions but different energies. In the interpretation made by @Akgun2018a, the lower energy state for each series of degenerate models (i.e., A1, B1 and C1) corresponds to stable configurations, while high energy states (i.e., A2, B2, C2 and C3) may be unstable 