资源环境科技发展态势分析平台

We assess the impact of split-flow blocking in the Australian region on global ocean wind waves using 30 years of high-resolution wave data from the CAWCR wave model hindcast. Statistically significant anomalies in significant wave height (H-s), peak wave period (T-p) and zonal wave energy flux (CgE) are found to covary with local variations in surface zonal wind induced by blocking at 140 degrees E. Strong negative anomalies in these wave fields highlight the role of blocking in promoting calm wave conditions around the Australian coast. A relatively weak but notable remote signal also appears in the Northern Hemisphere extratropics, suggesting a link to the Australian region via tropical forcing. The occurrence of daily low (below the 5th percentile) and high (above the 95th percentile) wave conditions also varies contemporaneously with blocking at 140 degrees E. Considering the ability of global circulation model forecasts to skilfully predict the blocking index out to at least 2 weeks lead time, our results point to blocking as a possible source of predictable wind-wave variability from sub-weekly to seasonal timescales.