Australia’s rainfall is highly variable, and long-term (100-plus years) observational records from rain gauges are limited, making it difficult to develop robust water policies and infrastructure that mitigates and adapts to future rainfall extremes. Relying solely on the severity of droughts and floods experienced since observations and meteorological record-keeping began in Australia for water-resource management decisions leaves communities, agriculture and industry vulnerable to infrastructure failure when the magnitude of future droughts or floods exceed previously experienced extremes.

In her 2022 paper, Danielle Udy led research that uses a method called ‘synoptic typing’ to group combinations of synoptic-scale weather systems (for example, high and low pressure systems) together to show that ice cores in East Antarctica and rainfall in Australia are connected by an ‘atmospheric bridge’. Summer seasons with increased sea-salt concentrations in the ice core and above-average rainfall conditions over subtropical eastern Australia are connected through the ‘atmospheric bridge’ that causes the following: increased wind speeds and sea-salt spray generation over the Southern Ocean near Law Dome; favourable conditions for widespread rainfall over mainland eastern Australia; and dry conditions over western Tasmania (for example, 2010/11 and 2021/22 summers with widespread flooding). In contrast, low sea-salt concentrations in the ice core are associated with synoptic-scale weather systems that cause hot and dry conditions over mainland eastern Australia and cool and wet conditions over Tasmania (for example, 2019/20 summer with severe bushfires). This study improves the understanding of the weather-scale processes linking the Law Dome ice core record to East Australian rainfall, which is vital for advancing how drought and flooding challenges are managed both currently and in the future.

Udy, D.G., Vance, T.R., Kiem, A.S., Holbrook, N.J., 2022. A synoptic bridge linking sea salt aerosol concentrations in East Antarctic snowfall to Australian rainfall. Commun Earth Environ 3, 175.