A 1D axisymmetric model for the tropical atmosphere and its seasonality

Despite decades of research into tropical dynamics, we lack a complete theory for the tropical circulation that explains Hadley cell, ITCZ, and monsoon dynamics altogether. A 1D axisymmetric model of an idealized dry atmosphere is presented to work towards this goal. Parameterizations of eddy momentum and heat fluxes, derived from literature and empirically validated against GCM simulations, are used in the momentum and thermodynamic equations. Seasonality is achieved by varying the latitude of maximum insolation through a prescribed meridional RCE temperature profile. The 1D model is run and compared against dry GCM simulations with identical RCE profiles across a range of seasonalities. We show that the 1D model is capable of reproducing many key features and behaviors of the tropical atmosphere. The model can be used to better understand the role of extratropical influences on the tropics by isolating the roles of the eddy heat and momentum fluxes, and understanding how their influences vary by season and other climate metrics.