Robust Yet Diverse Tropical Responses to Antarctic Meltwater Across Models

Continued melting of Antarctic ice sheets and shelves adds freshwater to the Southern Ocean (SO), enhancing stratification and inducing surface cooling. This cooling influences tropical climate through coupled atmosphere–ocean interactions, though model responses vary. Using coordinated coupled model experiments with idealized Antarctic meltwater forcing, we assess the remote impacts of SO surface cooling. All 11 models simulate equatorial surface cooling and a northward Intertropical Convergence Zone shift, but show discrepant responses in the equatorial Pacific zonal temperature gradient and Atlantic meridional dipole. When normalized by SO cooling amplitude, these tropical metrics are positively correlated with shortwave cloud feedback strength. Surface energy budget analysis indicates that the previously proposed teleconnection mechanisms in the eastern Pacific are not robust across models. The timescale of tropical cooling and the relative roles of wind-driven latent heat and shortwave fluxes differ across models and basins, highlighting the uncertainty in SO–tropics teleconnections.