Global Warming in an Idealised Dry Model with a Realistic Stratosphere

The importance of changes to the mean state of the stratosphere driven by increased concentrations in greenhouse gasses to tropospheric dynamics has been shown in many previous studies. We use an idealised dry primitive equation model forced with Newtonian cooling to a ``perpetual-January'' prescribed equilibrium temperature profile and a simple relaxation style convection scheme to simulate a global warming signal. A radiative equilibrium stratospheric temperature profile based off radiative transfer calculations provides a realistic mean-state temperature profile for the stratosphere. The resulting changes in the tropospheric extratropical circulation are studied. The individual contribution of both radiative and lapse-rate changes due to convection are determined as well as the influence of the stratosphere on the troposphere. The effect of enhanced surface polar warming in the Northern Hemisphere are also studied.