Vertical profiles of acetylene (C₂H₂, solid), ethane (C₂H₆, long dashed), methylacetylene (CH₃C₂H, short dashed), propane (C₃H₈, dotted), diacetylene (C₄H₂, long dash-dotted), ethylene (C₂H₄, short dash-dotted), and methane (CH₄, double dashed lines). The black line represents our computation results under the quiescent atmospheric conditions at 15°S. The profiles retrieved by Guerlet et al. (2009, 2010), with associated one-sigma uncertainties shown to the right and left of the derived profiles, are plotted in blue. There are no observational data for C₂H₄ in quiescent conditions.