Unprecedented high northern Australian streamflow linked to an intensification of the Indo-Australian monsoon

However, because of limited data availability, it is hard to assess this recent trend and therefore contextualize potential future climatic changes. In this study, we used a network of 63 precipitation-sensitive tree-ring chronologies from the Indo-Australian and Asian monsoon regions to reconstruct streamflow in the Daly catchment in the Northern Territory of Australia from 1413 to 2005 CE.

We used a novel wavelet-based method to transform the variance structure of the tree-ring chronologies to better match the hydroclimate prior to reconstruction with a hierarchical Bayesian regression model. Our streamflow reconstruction accounts for 72%-78% of the variance in the instrumental period and closely matches both historical flood events and independent proxy records, increasing confidence in its validity. We find that while streamflow has been increasing since the 1800s, the most recent 40-year period is unprecedented in the last similar to 600 years.