The wave climate of Bass Strait and South-East Australia

A high-resolution third-generation wave model based on unstructured grids, WAVEWATCH III, was used to investigate the wave climate of Bass Strait and South-East Australia over the period 1981 to 2020. The model results are extensively validated against a network of coastal buoys and demonstrate that the model can capture the overall wave characteristics in this region. Analyses of model outputs across the 40-year period show that significant wave height has increased by approximately 5% and a slight counterclockwise rotation of peak wave direction has occurred with likely implications for coastal processes. Seasonal variations show higher significant wave height in winter compared to summer, which is driven by dominant Southern Ocean swell. The peak wave direction in the eastern region shifts from south-westerly in winter to south-easterly in summer. In autumn and winter, there is a statistically significant correlation between wave conditions and the Southern Annular Mode. During these seasons, a southward movement of Southern Ocean low pressure systems is associated with increased significant wave height, an increase in the peak wave period and a counterclockwise rotation of the peak wave direction.

Automated summary

A high-resolution third-generation wave model, WAVEWATCH III, was used to study the wave climate in Bass Strait and South-East Australia. The model results were validated against coastal buoys and showed an overall agreement. The study found that significant wave height has increased by approximately 5% over a 40-year period and a slight counterclockwise rotation of peak wave direction has occurred. Seasonal variations show higher wave height in winter compared to summer, driven by Southern Ocean swell. The Southern Annular Mode is found to be correlated with wave conditions during autumn and winter.