The climatological atmospheric circulation is key to establishing the tropical ‘pattern effect’, whereby cloud feedbacks induced by sea surface temperature (SST) warming depend on the spatial structure of that warming. But how patterned warming-induced circulation changes affect cloud responses is less clear. Here we use idealized simulations with prescribed SST perturbations to understand the contributions to changes in tropical-mean cloud radiative effects (CRE) from different circulation regimes. We develop a novel framework based on moist static energy to understand the circulation response, targeting in particular the bulk circulation metric of ascent fraction. Warming concentrated in regions of ascent leads to a strong ‘upped-ante’ effect and spatial contraction of the ascending region. Our framework reveals substantial contributions to tropical-mean CRE changes not only from traditional ‘pattern effect’ regimes, but also from the intensification of convection in ascent regions as well as a smaller contribution from cloud changes in convective margins.

Uncertainty in the response of clouds to global warming remains a significant barrier to reducing uncertainty in climate sensitivity. A key question is the extent to which the dynamic component -- that which is due to changes in circulation rather than changes in the thermodynamic properties of clouds -- contributes to the total cloud feedback. Here, simulations with a range of cloud-resolving models are used to quantify the impact of circulation changes on tropical cloud feedbacks. The dynamic component of the cloud feedback is substantial for some models and is controlled both by SST-induced changes in circulation and nonlinearity in the climatological relationship between clouds and circulation. Differences in the longwave and shortwave dynamic components across models are linked to the extent to which ascending regions narrow or expand in response to a change in SST. The diversity of changes in ascent area is coupled to intermodel differences non-radiative diabatic heating in ascending regions.