Poul Christoffersen: A stochastic parameterisation for iceberg calving in pyISSM
Protection of nature, infrastructure, and communities across low-lying parts of Australia relies on well-designed coastal adaptation strategies and protection measures that take sea level rise into account. These mitigation efforts are hindered by deep uncertainty in the projection of sea level rise, notably in Antarctica where tipping points make future ice losses extremely uncertain. A key tipping point, which is poorly understood, is iceberg calving. The current generation of ice sheet models rarely capture icebergs, which break off ice shelves and glaciers that terminate in the sea when fractures propagate and ice becomes damaged. Here we report preliminary results from an ARC Discovery Project which is working to develop an improved calving parametrisation in pyISSM. The work brings together different types of modelling strategies, starting with highly resolved simulations of the fracture mechanism. Our aim is a calving function that integrates damage processes so that icebergs of vastly different sizes and shapes to be stochastically generated, and validated.