Abstract
Climate feedbacks, key determinants of Earth’s temperature response to radiative forcing, remain uncertain, largely because of challenges in representing cloud and convective processes. Global storm-resolving models (GSRMs), which explicitly simulates storm-scale convective circulations, have recently emerged as a promising alternative to conventional general circulation models to reduce uncertainties in clouds, convection, and possibly also climate feedbacks. Here, we perform control and +4K sea surface temperature perturbation experiments at two horizontal resolutions to evaluate climate feedbacks in the ICOsahedral Non-hydrostatic model (ICON) GSRM with convection parameterization disabled and compare them with models from the Coupled Model Intercomparison Project phase 6 (CMIP6), and two independent GSRMs. The results indicate that ICON has a more negative net feedback, yet a more positive cloud feedback compared to the majority of CMIP6 models. At the same time, even when ICON’s net or net cloud feedbacks resemble those of other GSRMs, the underlying shortwave and longwave contributions diverge, underscoring the model-dependent nature of cloud feedbacks in GSRMs. Spatially, ICON’s cloud feedbacks display characteristic regional contrasts driven by well-known processes, including rising cloud tops, reduced tropical cloud anvils, enhanced land-sea warming contrasts, strengthening of convergence zones, decreased stratocumulus cloud cover, increased low-cloud reflectivity in marine stratus regions and the extratropics. Finally, despite variations in simulation length, ICON’s climate feedbacks, and the processes underlying them, remain remarkably consistent across resolutions. These findings highlight the need for coordinated GSRMs intercomparisons to better constrain real-world climate feedback estimates.