AGS-PRF: Atmospheric Blocking Variability Associated with the Madden-Julian Oscillation in Present and Future Climates

Henderson, Stephanie A, Fort Collins CO

Investigators

Abstract

Atmospheric blocks are quasi-stationary large-scale anti-cyclonic circulation patterns in the upper troposphere that interrupt the westerly jet steam circulating in mid-latitudes. Due to their relatively long lifetimes of up to several weeks, blocking flows are capable of making weather systems that migrate along the westerly jet become stagnant over the same regions, sometimes causing extreme events such as heat waves, droughts, and floods. This project, building on the PI's Ph.D. dissertation research, investigates the connection of extratropical blocks to the Madden-Julian oscillation (MJO), a prominent intra-seasonal (30-60 days) form of variability in the tropical atmosphere. A linear inverse modelling (LIM) approach is used to identify tropical diabatic heating anomalies associated with MJO that can evolve into blocking flows in the extratropics. The research could be beneficial to regional decision makers by demonstrating how blocking events in a given region can be traced back to MJO events in the tropics, thus enabling advanced warning of blocking events and their impacts. In addition, the project supports a postdoctoral researcher who is at the beginning of her scientific career, thereby providing for the future scientific workforce in this area.