  In this study, we employ a cloud-resolving model (CRM) to investigate how
gravity influences convection and clouds in a small-domain (96 km by 96 km)
radiative-convective equilibrium (RCE). Our experiments are performed with a
horizontal grid spacing of 1 km, which can resolve large (> 1 km$^2$)
convective cells. We find that under a given stellar flux, sea surface
temperature increases with decreasing gravity. This is because a lower-gravity
planet has larger water vapor content and more clouds, resulting in a larger
clear-sky greenhouse effect and a stronger cloud warming effect in the small
domain. By increasing stellar flux under different gravity values, we find that
the convection shifts from a quasi-steady state to an oscillatory state. In the
oscillatory state, there are convection cycles with a period of several days,
comprised of a short wet phase with intense surface precipitation and a dry
phase with no surface precipitation. When convection shifts to the oscillatory
state, water vapor content and high-level cloud fraction increase
substantially, resulting in rapid warming. After the transition to the
oscillatory state, the cloud net positive radiative effect decreases with
increasing stellar flux, which indicates a stabilizing climate effect. In the
quasi-steady state, the atmospheric absorption features of CO$_2$ are more
detectable on lower-gravity planets because of their larger atmospheric
heights. While in the oscillatory state, the high-level clouds mute almost all
the absorption features, making the atmospheric components hard to be
characterized.
