Examples of He I 10830 Å intensity profiles found at the leading front of the flare ribbon. The dots represent the observed profiles and the red solid line is the fit from the HAZEL inversions. The quiet-Sun profile, which is at rest, is shown in gray to better identify the Doppler shifts. The positions of the four profiles (α, β, δ, and γ) appear in Fig. 5; the inferred velocities are −10.0, −5.8, 10.9, and −9.1 km s⁻¹, respectively. In panel α, the absorption seen in He I is the blueshifted component, whereas the He I emission profile is the redshifted component.