Temperature and eddy diffusion coefficient profiles used in this study. The K(z) profile is plotted in black. The brown temperature profile comes from Guerlet et al. (2009) and corresponds to 15°S. We used this profile as our baseline profile to validate the model in quiescent conditions. The other profiles result from retrievals performed on measurements in the beacon at 40°N and are taken from Fig. 8a of Fletcher et al. (2012a). We used these profiles to model the temporal evolution of hydrocarbon abundances in the beacon, following the timeline presented in Fig. 4 (see Sect. 3).