Proton number density (upper panel), wind speed (middle panel), and temperature (lower panel) of our slow and fast wind models. As in Fig. 2, the black and red lines corresponds to the slow and fast winds respectively. The dashed lines in the upper and lower panels show the Helios A and Helios B measurements of the slow and fast wind properties, as described in Sect. 3.2. The dotted line in the middle panel shows the radial speed profile of the slow wind estimated by Sheeley et al. (1997). The line corresponds to , where v_a = 418.7 km s^-1, r_a = 15.2R_⊙, and r₁ = 4.5R_⊙.