Speaker: Zane Karas Martin from Columbia University

Title: "Modeling the relationship between the Madden-Julian oscillation and the quasi-biennial oscillation"

Abstract: Recent observational studies have demonstrated a strong and surprising link between two key modes of tropical variability: the Madden-Julian oscillation (MJO) and the stratospheric quasi-biennial oscillation (QBO). After briefly reviewing these two phenomena, we discuss the main components of the MJO-QBO relationship, including the key takeaway that when QBO winds in the lower stratosphere are easterly, the MJO tends to be stronger and more predictable during boreal winter. We then present two modeling studies that explore whether the observed MJO-QBO link can be captured in two different numerical models and configurations: a small-domain cloud-resolving model, and a global forecast model. In both cases, we find that models struggle to clearly demonstrated the strong observed link, though show some weak signs of an MJO-QBO connection. The continuing challenge of realistically capturing the MJO-QBO link for a wide range of models is discussed, as well as the implications for the observed relationship and possible directions for future work on this topic. Related paper 1, 2