Specific angular momentum of gas at t = 400 T₀ from models with different vertical prescriptions of the α parameter. Panels a, d, and g: Models in which α = 10⁻³, 10⁻⁴, and 10⁻⁵, respectively. Panel b: Model in which α decreases from 10⁻³ in the midplane to 10⁻⁴ in the atmosphere. Panel c: Model in which α increases from 10⁻⁴ in the midplane to 10⁻³ in the atmosphere. Panel e: Model in which α decreases from 10⁻⁴ in the midplane to 10⁻⁵ in the atmosphere. Panel f : Model in which α increases from 10⁻⁵ in the midplane to 10⁻⁴ in the atmosphere. Last panel: Corresponding vertical profiles of α.