Radial profile of ¹³CO and C¹⁸O J = 2−1 lines for four T Tauri models where ψ = 0.1, h_c = 0.1, M_disk = 10^-3 M_⊙ and R_c and γ assume different values. Models with γ = 1.5 are presented in dark blue, while those with γ = 1.0 are shown in light blue. Solid lines displays models with R_c = 30 au and dotted lines represents those with R_c = 200 au. These line profiles are obtained assuming a distance of 100 pc, an inclination angle i = 10°, and by convolving the output images by a 0.5′′ beam. The horizontal dashed lines show the typical ALMA sensitivity for an integration time of 1.84 h on source for a 0.2′′ beam (purple line) and for a 0.5′′ beam (pink line), given a spectral resolution of 1.3 km s^-1.