Same as Figure 3, but with other parameters varied. (a) A series of models with anomalously strong Coulomb collisions, with a range of constant multipliers f to the classical collision frequency (see labels). (b) Models computed over a range of colatitudes θ in the heliosphere, which affects the Parker spiral angle Φ (see Equation (10)). The standard model with wind speed u = 700 km s ⁻¹ is shown in both panels (thick red line).