Initial quasi-steady coronal streamer and ambient solar wind. (a) Lower-boundary radial magnetic field, B_r, as a function of θ. (b) Flow speed, V, Alfvén speed, V_A, and sound speed, C_s, along the open field line highlighted in green in panels (c) and (d). (c) Density and (d) radial velocity in a meridional plane, overlaid with magnetic field lines.