Effects of background gases on hurricane formation. From (a) to (e), these are snapshots of instantaneous surface air pressure (hPa) under background gases of H₂, He, N₂, O₂, and CO₂, respectively.In all these experiments, the planetary rotation period is one Earth day and surface temperature is uniform (301 K). Forexperiments with a rotation period of three Earth days, the results are the same except that the hurricanes are larger insize but fewer in number in the latter three experiments.