Australia — In a new research, scientists have established a link between bushfires in Australia and Indian Ocean conditions.
Southeastern Australia has been hit by several serious bushfires in recent years, including the devastating February 2009 Black Saturday fire, which killed more than 170 people.
To improve understanding of how climate change may affect the occurrence of bushfires, W. Cai from the CSIRO Marine and Atmospheric Research, Aspendale, Victoria, and colleagues examined the connection between bushfires and positive Indian Ocean Dipole (pIOD) events.
Such events are a phase in which the eastern Indian Ocean is cooler than usual while the western Indian Ocean is warmer than usual.
These conditions tend to lead to lower than average rainfall and higher temperatures over southeastern Australia.
The researchers found that pIODs reduce the soil moisture, increasing the fuel load leading into summer.
Furthermore, they show that of 16 pIOD events since 1950, 11 were followed by major bushfires, and of the past 21 major bushfires, 11 were preceded by pIOD.
The researchers also found that bushfires are more strongly associated with pIOD events than with El Nino events.
Because global warming is likely to increase the frequency of pIOD events, the researchers suggest that bushfire risk will also increase.