Panel a: sketch of the global situation (upper panel: rest frame; lower panel: frame of reference rotating with the Sun); for details, see the main text. Panel b: schematic presentation of the geometry and CIR characteristics (fixed reference frame), as applied in the model (x₀ and x_e represent the beginning and end of CIR and HSS at 1 au, respectively; for details, see the main text). Panel c: dependence of the radial CR-gradient, G_r, for three specific s/c positions (x₁, x₂, x₃) as a function of heliocentric distance, r. The heliocentric distance of the CIR frontal edge for the three specific s/c positions, x_i, are denoted r₁, r₂, r₃. Panel d: corresponding radial distance dependence of the cosmic ray count rate, Φ_xi(r), between CIR and HSS outer boundary and s/c. The red line marks the behavior in a quiet-Sun situation at the CIR outer boundary. Panel e: sketch of the resulting Forbush decrease profile, Φ(t), as measured by the s/c.