Modulation of the Bifurcation in Radiative‐Convective Equilibrium by Gray‐Zone Cloud and Turbulence Parameterizations

This study investigates the mechanisms by which small-scale turbulence and cloud physics determine organization of large-scale convection in radiative-convective equilibrium (RCE), an idealization tropical atmosphere. Under uniform forcings similar to typical conditions, atmosphere RCE might spontaneously separate into dry moist regions on scales 100–1,000 km, with convective clouds aggregating a cluster latter. phenomenon is known as self-aggregation. Herein, we demonstrate that subtle changes assumptions related 1 km can dictate emergence or suppression self-aggregation, resulting from bifurcation dynamical system. The occurs when small patch forms domain sustained because it contributes negative effective diffusivity circulation. Cloud-radiation feedbacks circulation interactions govern formation such patches, thereby modulating bifurcation. sensitive dependence subgrid process models be fundamental barrier climate predictability light inherent uncertainties microscale processes. Because without capability include exact representations those processes models, slight differences different approximations used modelers lead qualitative predictions, at least for some