This time last year, the last of 3 consecutive La Niñas were soaking much of Australia. Twelve months on, the land is parched, and parts of southern Queensland and NSW are in the midst of a bushfire crisis. The climatic flip-flop from 2022 to 2023 has been a doozy.
So how did we get here? From flooding rains to drought-like conditions, the transition from wet to dry is shaping up to be a real-world example of a key area of research focus in our project Extremes: dry, wet, hot-and-dry.
We often think of drought-like conditions as being slow to emerge; with drought indicators, like soil moisture, drying out over the course of a few months. But the reality is that transitions to dry conditions are dynamic. Sometimes drying can be rapid, transitioning from near-normal conditions to very dry conditions in the space of 2-4 weeks, rather than 2-4 months. It is the most rapid of these transitions – periods of rapid drying – that we’re investigating through this work.
These events have peaked scientific interest in recent years because they can result in a phenomenon called “flash drought”. Representing one part of the drought spectrum, flash droughts can transition the landscape from near-normal into drought-like conditions in less than a month. Consequently, these droughts often develop with very little warning and have the potential to bring about significant consequences for the landscape.
That’s why our project team is investigating these periods of rapid drying, including flash drought. Anecdotally, rapid drying episodes include periods of extreme heat and elevated bushfire activity, exactly like what we’re currently seeing in southern Queensland and northern New South Wales.
We’re working towards understanding how fast the Australian landscape can dry out and the types of overlying atmospheric conditions that cause this to happen. We’re also looking at the types of impacts this has ‘on-the-ground’, by quantifying connections to periods of extreme heat and bushfires. Understanding what causes periods of rapid drying will give us the fundamental knowledge to understand how these events will be affected by climate change. As the world warms, this is crucial knowledge to be able to manage impacts on the ground.
If a rapidly drying landscape, or flash droughts, affect you, please make sure to get in touch or see last week’s webinar on Drying out, the summer ahead and beyond.
Associate Professor Ailie Gallant
Read more in the latest e-newsletter.
For news, research, resources, publications and events from the Climate Systems Hub, sign up here.