A/Prof. Ivica Janekovic¹, Prof. Charitha Pattiaratchi¹

¹UWA, Perth, Australia

In many coast applications, we strive to estimate and predict correct ocean dynamics at the best possible spatial and temporal resolutions as all other engineering activities rely on the correct physics. Computing ocean currents in a full 3D sense, sea level variations, or coupling all that together with the wave dynamics are commonly on wish lists for the major inputs into the design criteria, planning or operability studies.

In this talk, I will walk you on the journey from the global ocean modelling systems all the way down to a local 2-way coupled hydrodynamic-wave 3D system with up to ~10m spatial resolution. Along the way I connected different models (finite difference NEMO , ROMS, WRF, WW3, and finite element SCHISM, WWM), different time stepping (explicit and implicit), and different nesting techniques to get as close as possible to reality. As an example, I will show you the results of a such system for the latest storm event (beginning of August 2022) that smashed at WA and Perth coastal waters inducing significant waves ~ 10m at the Rottnest buoy and ocean currents in the coastal regions stronger than 1,5 m/s. Benefits of the ultra fine-resolution coastal system are evident in high-detail maps of fine features related to the propagation of the wave energy and for example surface and bottom ocean currents relevant for port planning and/or sediment/biology studies.

All the simulations were made on the new Pawsey Setonix supercomputer and could integrate even into the real-time system (we needed 1 day of a wall clock to simulate 45 days of simulation using 256 cores).

Biography:

I am a physical oceanographer with more than 20y of experience in the observations and modelling space. I am developing 4D-Var Data Assimilation, ROMS nesting, 2-way ocean-atmosphere-wave coupling, and real-time applications systems in different parts of the World. Solving industry-related problems, developing High-Performance Computing models, leading many projects, and publishing my work are the core of my activity.  Currently, I am working as a Research Associate Professor at the Oceans Graduate School, University of Western Australia.