Top panel: temperature map at the limb of WASP-121b as predicted by a solar composition SPARC/MITgcm. The east limb is at an azimuth of 0°. The condensation curves of several possible condensates have been overplotted. The atmosphere should be cloudy where it is cooler than the condensation curve. Bottom panel: transmission spectrum of WASP-121b corresponding to the above temperature map with and without taking CaTiO₃ clouds into account. We assume a particle size of 0.1 μm, that the particles neither settle nor are transported by the circulation, and that the number of particles is given by the mass conservation of condensed Ti atoms. The models are compared to data taken from Evans et al. (2016).