Picture (above): Kings Canyon, Petermann, Australia by Phillipe Wuyts (Unsplash).

Research focused on the Northern Hemisphere has demonstrated that unusually dry soils preceding a heatwave event amplify the hot conditions. However, we don’t know whether the daily evolution of how the land surface dries out can amplify heatwave temperatures, or whether any impact is similar across a large area like Australia.

In exploring these knowledge gaps, CLEX researchers found that regions where there is a larger drying trend tend to be more sensitive to land water availability and have more heatwave days. They found that the effect of dry soils before a heatwave varies considerably across Australia.

Identifying where dry soils have a large impact on heatwaves required classifying the land into regions where soil water variability affects surface temperatures and where it doesn’t. This could be extended to other atmospheric processes to differentiate between local and remote influences.