Ice Sheet Dynamics and Climate Interactions in Sea Level Changes

Ice sheet dynamics encompass the processes governing the flow, melting and mass balance of the Greenland and Antarctic ice sheets, which together hold enough water to raise global sea levels by several metres. Surface melting, driven by atmospheric warming and enhanced by episodic events such as foehn winds and atmospheric rivers, delivers freshwater to the ice surface and promotes runoff. Beneath the ice, ocean-driven basal melting of floating ice shelves undermines their buttressing effect, accelerating grounded ice discharge. The grounding line, where ice detaches from bedrock to float, is sensitive to ocean heat and bed topography; its retreat can trigger marine ice sheet instability in regions underlain by retrograde slopes. Iceberg calving at ice fronts further contributes mass loss, with rates controlled by both ice flow and fracture regimes. Together, these interactions dictate the mass budget of ice sheets, influencing the rate and magnitude of sea level rise. Advances in remote sensing, high-resolution modelling and process studies have refined projections of future change, underscoring the global importance of mitigating greenhouse gas emissions and improving predictions of coastal impact.

Research from Nature Portfolio

Recent studies have revealed that intense melt events in northeast Greenland are strongly linked to atmospheric rivers impinging on the coast, which induce foehn winds and explain up to 100% of extreme melt during such episodes. These findings demonstrate an increasing frequency of high-melt conditions in the twenty-first century, with a growing contribution to annual mass loss and sea level rise. In Antarctica, regional ocean simulations project a committed tripling of ice-shelf melting in the Amundsen Sea sector over the coming decades under all emissions scenarios. This unavoidable increase in basal melt highlights a limited capacity for mitigation to prevent the destabilisation of key ice shelves and the potential collapse of the West Antarctic Ice Sheet.

Research from all publishers

A comprehensive assessment of Antarctic ice shelves from 1997 to 2021 partitioned annual mass budgets into basal melting and calving components. Out of 162 shelves, 71 showed significant mass loss, with basal melt dominating losses in over two-thirds of cases. This partitioning underscores spatial variability in contributors to ice-shelf health and the importance of detailed component analysis. A recent review of iceberg calving identified five persistent calving regimes, each controlled primarily by ice flow past restraining points rather than by brittle fracture processes alone. Transitions between regimes represent the largest uncertainty in sea level projections, as they can trigger abrupt increases in calving rates. A four-decade reconsolidation of Antarctic mass balance using satellite altimetry and ice-velocity data revealed a four-fold acceleration in mass loss since the 1980s, driven by increased oceanic heat delivery and grounding line retreat. These trends confirm a growing contribution of Antarctic ice loss to global sea level rise and the critical role of bed topography and ocean circulation in controlling stability.

Ice Sheet Dynamics and Climate Interactions in Sea Level Changes publication trend

The graph below shows the total number of articles in ice sheet dynamics and climate interactions in sea level changes across all publications each year (not limited to Nature Index journals).

Technical terms

Ice shelf: A floating extension of an ice sheet that exerts back-stress on grounded ice, stabilising inland flow.

Grounding line: The junction where ice resting on bedrock detaches and begins to float, a key control on marine ice sheet stability.

Atmospheric river: A narrow, long-range corridor of enhanced water vapour transport in the atmosphere that can deliver intense precipitation or melting.

Foehn wind: A warm, dry downslope wind that can elevate surface temperatures and amplify melt on ice sheet margins.

Iceberg calving: The process by which blocks of ice fracture and detach from a glacier terminus or ice shelf, contributing directly to mass loss.

Basal melting: Melting of the underside of floating ice shelves due to contact with relatively warm ocean waters, reducing structural integrity.

References

1. Increasing extreme melt in northeast Greenland linked to foehn winds and atmospheric rivers. Nature Communications (2023).
2. Unavoidable future increase in West Antarctic ice-shelf melting over the twenty-first century. Nature Climate Change (2023).
3. Annual mass budget of Antarctic ice shelves from 1997 to 2021. Science Advances (2023).
4. Iceberg Calving: Regimes and Transitions. Annual Review of Earth and Planetary Sciences (2023).
5. Four decades of Antarctic Ice Sheet mass balance from 1979–2017. Proceedings of the National Academy of Sciences of the United States of America (2019).