Normalized contribution functions at the line center for the CO (J=3–2) line observed with SMA in March 2010 (dotted black line) and CO (J=2–1) line observed with ALMA in January 2012 (long-dashed, dark blue line). Contribution functions are also presented for the CO (J=2–1) line for 1 MHz (shortdashed, light blue line) and 4 MHz (dashed-dotted, yellow line) frequency offsets with respect to the line center. The wind contribution function pertaining to the CO (J=2–1) observations is plotted with a solid red line. All contribution functions are calculated at the equatorial planet limb with the rescaled 220-year-old-comet-impact profile of Cavalié et al. (2010) and account for the relevant spatial and spectral convolutions.