The role of Antarctic basal meltwater

Freshwater hosing experiments are a widely used tool for understanding the impacts of Antarctic ice shelf basal melting on the Southern Ocean and global climate. Most existing coupled climate models lack the necessary physics to explicitly simulate basal melting. Therefore, freshwater anomalies have to be imposed as a proxy. Previous studies have employed diverse freshwater scenarios and application methods. In this study, we explore variations in the application and representation of meltwater anomalies around Antarctica. We compare simulations where freshwater anomalies are introduced at the ocean surface over different spatial extents and at specified depths along the continental slope for a more realistic representation of plume dynamics resulting from basal melting. Additionally, we investigate ocean heat fluxes variability when accounting for the latent heat of fusion required to melt the ice. It is possible to observe similarities and differences in ocean responses depending on the methodology used to impose the freshwater anomaly. Surface application scenarios tend to exhibit more diffuse impacts on ocean stratification and circulation, while depth-specific applications lead to localized but more intense changes in water mass transformation. Accounting for latent heat can introduce further complexity, altering the thermal structure and influencing buoyancy-driven dynamics. By comparing these approaches, we want to highlight the sensitivity of simulated ocean dynamics to the spatial and physical representation of meltwater inputs. Accurately parameterizing ice-ocean interactions in models is necessary to improve the reliability of projections regarding Antarctic contributions to sea level rise and global climate variability.