Heatwaves in south-eastern Australia are known to be associated with surface high-pressure systems over the Tasman Sea and anticyclonic anomalies in the upper troposphere above south-eastern Australia. However, these features are often transient and do not form in place.
This is contrary to the way we normally investigate heatwaves, which only consider heatwave days in a particular place or small region. In this paper, CLEX researchers introduce a way of investigating heatwaves that allows for the heatwave region to move and use this tool to look at summer heatwaves in south-east Australia.
They found that heatwaves in south-east Australia are part of an area of hot weather that moves from west to east along with the surface and upper-tropospheric weather patterns, and many of the heatwaves seen in south-eastern Australia are part of moving weather system that has led earlier to hot weather across southwestern Australia.
This suggests that majority of heatwaves affecting south-eastern Australia are part of large and strong weather systems propagating across Australia, and not due to stationary or blocked weather systems as seen in some other regions of the world.
- Paper: King, MJ, Reeder, MJ. Extreme heat events from an object viewpoint with application to south‐east Australia. Int J Climatol. 2021; 1– 17. https://doi.org/10.1002/joc.6984