Meteorological drought development, intensification and termination mechanisms: an Australian review

Over the last decade, our understanding of meteorological drought has evolved from an understanding of the mechanisms causing droughts to develop, to include an understanding of how they intensify and terminate. In this review, we show that the understanding of Australian drought has evolved from one that associates drought primarily with large-scale processes typically related to low precipitation, towards an understanding of the importance of processes that promote heavy to extreme precipitation. It is now understood that Australian meteorological droughts develop and intensify largely through a sustained absence of synoptic systems responsible for strong moisture transport and ascent, together with an absence of wet phases of large-scale modes of climate variability. The return of these heavy precipitation-promoting processes is key to drought termination, and can play a role in post-drought flooding. This presentation will summarise this new mechanistic understanding of Australian meteorological drought, drawing on observational, climate model and machine learning-based research. Furthermore, this presentation will outline a research agenda to address identified knowledge gaps to better the understanding, simulation and prediction of drought in Australia and around the world.