Decoupling the Subtropical Jet from the Hadley Cell in Idealized Atmospheric Models

Abstract:

Recent research shows the subtropical jet (STJ) is not dynamically coupled to the edge of the Hadley Cell (HC) as current theory would predict. Up to now, this conclusion has been revealed in output from coupled climate models and reanalysis data, but not in idealized atmospheric models. In our study, we explore this distinction between modelling platforms as it provides insight into the processes responsible for such a disconnect. We demonstrate that decoupling the STJ from the HC is possible in a purely dry atmospheric model as a result of zonal variability, a zonally symmetric model is thus limited in its ability to reproduce the same behavior. Further work is done to discern the relative importance of zonal variability due to topography versus variations in the equilibrium temperature profile.