Brief communication: Sensitivity of Antarctic ice shelf melting to ocean warming across basal melt models

Abstract

The uncertain sensitivity of Antarctic ice shelf basal melt to ocean warming strongly contributes to uncertainties in sea level projections. Here, we explore the response of five basal melt models to an idealised subthermocline warming. Total melt increases by 67 %-240% (C1 °C) or by 141 %-680% (C2 °C), showing a large intermodel spread. For deep regions of presently fast-melting ice shelves, this spread can reach 2 orders of magnitude. Therefore, a consistent calibration to present-day conditions does not guarantee consistent melt sensitivities, and several basal melt forcings should be applied to prevent underestimating uncertainties in sea level projections.