Wave structures in simulation run C. (a) Plasma density variation, n_e− < n_e >, in the x–z plane for t = 300 ms. The subtracted mean, < n_e > is formed over the region shown. The circle in the centre has been removed as the high density in that region would otherwise dominate the mean. (b) Singular value decomposition (SVD) of the plasma density at t = 100 ms with the first four principal images removed. (c) SVD of the plasma density at t = 200 ms. (d) SVD of the plasma density at t = 300 ms. (e) The E_x component of the electric field at t = 300 ms. (f) SVD of the E_x component of the electric field at t = 300 ms. (g) SVD of the current density magnitude |j| at t = 300 ms. (h) SVD of the magnitude of the in-plane electric field, , at t = 300 ms. The black arrows in panels d and h show the direction of the current density.