Effects of Circulation on Tropical Cloud Feedbacks in High‐Resolution Simulations.

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 analyzed 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 sea surface temperature (SST) induced changes in circulation and nonlinearity in the climatological relationship between clouds and circulation. We find notable inter‐model differences in the extent to which ascending regions narrow or expand in response to a change in SST, which we link to differences in the longwave and shortwave dynamic components across models. The diversity of changes in ascent area is coupled to intermodel differences in non‐radiative diabatic heating in ascending regions. Plain Language Summary: Clouds influence Earth's energy balance by absorbing and reflecting solar and terrestrial radiation. The response of clouds to warming remains a key source of uncertainty in understanding how the climate system will evolve. In particular, how the influence of clouds on radiation is coupled to the atmospheric circulation is an open question. In this study, idealized simulations of the tropics at high spatial resolution (3 km) are analyzed to probe how changes in circulation impact clouds in a warming climate. It is found that, across a range of models, the degree to which circulation changes influence clouds depends on how the area of the region with ascending air responds to warming. Key Points: Influence of circulation changes on cloud feedbacks is substantial in some cloud‐resolving modelsComponent of cloud feedback associated with circulation changes is coupled to ascent areaIntermodel spread in response of ascent area linked to non‐radiative diabatic heating [ABSTRACT FROM AUTHOR]