Ratios of the proton heating rate to the total (proton + electron) heating rate. The standard model with wind speed u = 700 km s ⁻¹ is shown in both panels (thick red line). (a) Variation of the wind speed between 600 and 800 km s ⁻¹ in 50 km s ⁻¹ increments (see labels). (b) Models computed with T _small (dotted line) and T _large (dashed line) for the SWOOPS proton temperatures, and with Equation (7) for q _{∥, e} instead of the empirical fit (dot-dashed line).