Quasi-Biennial Oscillation influence on Australian summer rainfall

Abstract

Abstract The variability and distribution of Australia’s summer rainfall are influenced by modes of climate variability on multi-week to multi-year time scales. Here, we investigate the role of the stratospheric quasi-biennial oscillation (QBO) and demonstrate that the QBO influences rainfall variations and extremes’ responses across large regions of Australia. We find the QBO modulates convective heating to the east of the Maritime Continent and over the central South Atlantic Ocean in the austral summer. The baroclinic response and barotropic structure of the extra-tropical Rossby wave train induces anomalous circulation that affects the distribution and amount of rainfall over Australia. Our analysis and findings of QBO teleconnections with the dynamics that drive Australia’s rainfall variability and extremes represents a pathway to improve our understanding of rainfall potential predictability and scope to extend Australia’s rainfall prediction lead times.