Dr Vanessa Hernaman¹, Dr Kathleen McInnes¹, Dr Ron Hoeke¹, Dr Julian O’Grady¹, Dr Blake Seers¹, Ms Claire Trenham², Dr Xuebin Zhang³

¹CSIRO, Aspendale, Australia, ²CSIRO, Canberra, Australia, ³CSIRO, Hobart, Australia

Coastal ocean extremes, resulting from combinations of storm surge, waves, tides and regional sea level, cause billions of dollars of damage globally. Regions of Australia are particularly vulnerable to coastal hazards, and this will be exacerbated by climate change. Coastal hazard assessments are an essential tool to help understand, manage and prepare for coastal risk now and into the future. However, comprehensive risk assessments need to account for complex interacting coastal processes, provide information at high spatial/temporal scales, and be applicable to wide-ranging needs of coastal stakeholders. Coastal ocean models are key tools, allowing for the dynamic integration of relevant hydrodynamic processes. Here, we describe the development of a national-scale model to underpin the Australian Climate Service (ACS) Coastal and Flooding Hazards work package. The ACS is a $210 million project that aims to build and enhance Australia’s climate and natural hazard intelligence capability.

The national coastal model is a high-resolution two-way coupled hydrodynamic-wave model (SCHISM-WWMIII), which will be used to perform 40-year hindcast(s) and future time-slice projections of climate change and sea level rise (SLR) scenarios. The model utilises new forcing datasets being delivered jointly by the Bureau of Meteorology (BoM) and the CSIRO via ACS. These include a new global wave hindcast, new high-resolution regional atmospheric reanalyses/hindcasts/CMIP6 future climate projections, and latest developments in SLR projections. The model also benefits from insights gained from model development work within Bluelink (an operational partnership between BoM, CSIRO and Defence).

As well as the deterministic hindcast/time-slice national modelling, we will apply innovative synthetic tropical cyclone approaches for generating cyclone forcing applied to regional “tiles”. This work aims to provide greater understanding of future changes in waves, storm surge, SLR and associated coastal impacts at the national scale and provide stakeholder-relevant information to better understand coastal hazards under current and future climate.

Biography:

Dr Vanessa Hernaman is a research scientist in the Sea-Level, Waves, and Coastal Extremes team within the Climate Science Centre at CSIRO. Her research interests focus on using observations, coastal ocean modelling, and climate projections to better understand variability and change in the coastal ocean and associated potential impacts on coastal communities and ecosystems. She implements coupled hydrodynamic-wave models on climate timescales that underpin coastal hazard risk assessments. She also has operational experience through her previous role as a Senior Scientist in Ocean Forecasting at the UK Met Office.