Temperature (solid black line) and CH₄ profiles in Uranus. Red and green profiles are based on diffusion models. The blue curve is the empirical profile that simultaneously matches Herschel/PACS and Spitzer/IRS (see text). The thin dotted (dashed-dotted) line shows weighting functions in the core – 159.3 μm (wing – 159.0 μm) of the CH₄ line at PACS resolution, calculated for this solution profile. The Spitzer/IRS spectrum (Fig. 3) also constrains the CH₄ profile in the region of ~0.1 mbar.