Ice Shelf Mass Balance

Ice Shelf Mass Balance

Antarctic ice shelves moderate the contribution of the Antarctic Ice Sheet to global sea level rise by resisting the flow of ice into the ocean. Recent climatic shift around Antarctica has led to thinning and retreat of Antarctic ice shelves, which subsequently led to an increase in ice flux across the grounding line contributing to sea level rise. Ice shelves are therefore a key pillar to ice sheet-climate interaction. However, the mass budget, which is the balance of mass inputs from snowfall and grounding line discharge and mass exports from calving and basal melting, of Antarctic ice shelves has historically remained largely unknown. Through the ESA Polar+ IceShelves project an international consortium of scientists produced satellite observationally derived datasets of all key ice shelf mass balance variables, apart from the SMB parameter which was generated using a regional climate model. This enabled for the first time an almost entirely observationally driven Antarctic ice shelf mass balance assessment to be produced on all 162 ice shelves from 1997 to 2021.

Cumulative ice shelf mass change from 1997 to 2021 overlain on the 2010–2021 average ice shelf basal melt rates. Circle area is capped at 500 Gt and only ice shelves with significant mass change are plotted. Adapted from Davison et al. 2023.

Summary of the ice shelf mass balance datasets planned within 5DAIS:

• In 5DAIS we will make use of the existing methods to extend the ice shelf mass balance assessment forward in time to cover more recent years.
• This important dataset will feed into our scientific assessments of change around the Antarctic ice sheet margin, delivering important new information for high impact publications.