Insolation in Titan’s troposphere

Seasonality in Titan’s troposphere is driven by latitudinally varying insolation. We show that the latitudinal distributions of insolation in the troposphere and at the surface, based on Huygens DISR measurements, can be approximated analytically with nonzero extinction optical depths τ, and are not equivalent to that at the top of the atmosphere (τ = 0), as has been assumed previously. This has implications for the temperature distribution and the circulation, which we explore with a simple box model. The surface temperature maximum and the upwelling arm of thermally-direct meridional circulation reach the midlatitudes, not the poles, during summertime.

► Insolation’s latitudinal distribution in Titan’s atmosphere can be approximated analytically.
► The distributions in the troposphere and surface differ from that at the top of the atmosphere.
► The implications of these insolations are explored with a simple box model.
► Temperature maxima and upwelling oscillate between midlatitudes, not the poles, with season.