Inferences from Simple Models of Tropical Convection

Recent advances in understanding simple balances in the tropical atmosphere – including boundary layer quasi-equilibrium and the weak temperature gradient approximation – allow the construction of very simple representations of tropical circulation systems that involve deep convection. I will present some simple models of such systems that permit analytic solutions and provide a route to real conceptual understanding of the tropics. Topics covered will include the control of the humidity of the tropical atmosphere, the observed tight relationship between precipitation and column-integrated water vapor, the Walker Circulation, the diurnal cycle of convection over land, and self-aggregation of convection. By focusing on conceptual understanding, this work honors Peter Webster, his PhD thesis advisor Norm Phillips, and the legacy of the MIT School of the 1960s and 70s.