Picture: Drought. Credit: Tim J Keegan (Flickr CC BY SA 2.0)
‘The earth was brown, the sky was blue, No moisture fell, no drop of dew. … There a grey toad all parched and dead, Stuck in a crack with blistered head’Glenmaggie, 1888
Droughts in Australia can cause economic loss, crop failure and severe water shortages. Each drought has a different spatial and temporal footprint, so the more we can understand about past droughts, the better prepared we will be for future events.
However, the majority of current research looking at droughts in Australia only examines the 20th and 21st century, excluding severe dry events from the historical record. Studies that do include historical droughts generally focus on multi-year events, even though short droughts can also cause widespread loss and damage. To shed more light on short droughts of the past, CLEX researchers have taken advantage of a newly released dataset from the Bureau of Meteorology to re-examine the infamous Centennial Drought of 1888.
Using the new dataset along with historical station data, they analysed monthly rainfall variability across south-eastern Australia throughout 1888. They found declines occurred throughout the year, but particularly in April and early spring. The most severely affected regions were inland New South Wales and Victoria, as well as eastern Tasmania. The magnitude of the declines was similar to those observed in the recent drought (2017–2019), although not quite as severe as the devastating drought of 1982–83.
To investigate what may have caused these exceptional declines they interrogated historical climate indices data, building an idea of what the state of the climate system was at the time. They found that a strong El Niño event in the equatorial Pacific Ocean likely drove the strong declines seen in the second half of the year, while the precipitation pattern throughout the year was modulated by a positive phase of the Southern Annular Mode in the Southern Ocean. An anomalous increase in the intensity of the subtropical ridge of high pressure systems across the country may have also contributed to the low rainfall totals during 1888. This case study adds the 1888 Centennial Drought to our growing library of key events in Australia’s climate history, helping us understand the nature of our droughts and how they will change in a warmer world.
- Paper: Ritman Mathilde E. H. Ashcroft Linden C. (2020) Revisiting the 1888 Centennial Drought. Proceedings of the Royal Society of Victoria 132, 49-64. https://doi.org/10.1071/RS20004.