Radiative constraint and baroclinic adjustment in a gray radiation model

In a companion presentation we have introduced a theoretical framework for understanding the relevance of idealized radiative and baroclinic adjustment constraints for predicting the tropopause height. That work shows that the idealized radiative constraint may prevent baroclinic adjustment when the vertical heat transport is large, in which case the idealized radiative constraint is tightly satisfied. In contrast, when the vertical heat transport is small the idealized radiative constraint is only loosely satisfied and cannot prevent baroclinic adjustment. A transition between both limits can be obtained by changing the radiative-equilibrium stratification at the surface in the Newtonian cooling model.

In this work we study the robustness of these concepts by applying them to the same model forced using gray radiation. For most values of the radiative parameters, the gray radiation model tends to display a tight radiative constraint and very little sign of baroclinic adjustment. However, we have identified specific combinations of the radiative parameters for which the idealized radiative constraint becomes looser. In such settings there is a more pronounced tendency for the flow to produce a baroclinically adjusted equilibrium state.