We introduce the coupling of a sub-shelf melt model with an ice sheet model to explore how horizontal meltwater flow below ice shelves affects ice sheet mass loss over time. We show that accurately modelling the meltwater flow direction leads to distinct feedbacks and transient volume loss not captured by melt parameterisations that simplify flow direction. Our results highlight the importance of refining the meltwater flow representation in ice sheet models to improve sea level projections.

Ocean warming around Antarctica leads to ice melting and sea-level rise. The meltwater that flows into the surrounding ocean can lead to enhanced warming of the seawater, thereby again increasing melting and sea-level rise. This process, however, is not currently included in climate models. Through a simple mathematical approach, we find that this process can lead to more melting and greater sea-level rise, possibly increasing the Antarctic contribution to 21st century sea-level rise by 80 %.

The ice shelves in Antarctica are melting from below, which puts their stability at risk. Therefore, it is important to observe how much and where they are melting. In this study we use high-resolution satellite imagery to derive 50 m resolution basal melt rates of the Dotson Ice Shelf. With the high resolution of our product we are able to uncover small-scale features which may in the future help us to understand the state and fate of the Antarctic ice shelves and their (in)stability.

A major uncertainty in the study of sea level rise is the melting of the Antarctic ice sheet by the ocean. Here, we have developed a new model, named LADDIE, that simulates this ocean-driven melting of the floating parts of the Antarctic ice sheet. This model simulates fine-scale patterns of melting and freezing and requires significantly fewer computational resources than state-of-the-art ocean models. LADDIE can be used as a new tool to force high-resolution ice sheet models.

The Antarctic ice sheet (AIS) is the largest uncertainty in future sea level estimates. The AIS mainly loses mass through ice discharge, the transfer of land ice into the ocean. Ice discharge is triggered by warming ocean water (basal melt). New future estimates of AIS sea level contributions are presented in which basal melt is constrained with ice discharge observations. Despite the different methodology, the resulting projections are in line with previous multimodel assessments.