Research

Under global warming, both tropical cyclone activity and key sources of tropical cyclone predictability are expected to change. This research examines trends in subseasonal TC activity and its modulation by the Madden Julian Oscillation in both reanalyses and global climate models.

Western extensions of the Pacific subtropical high modulate the steering flow of Western North Pacific tropical cyclones. These westward extensions themselves are driven by large-scale sea surface temperature (SST) gradients. In our recent paper, we examine the mechanisms underlying two very similar SST patterns and the simulated atmospheric response in an atmosphere-only GCM.  

This JGR: Atmospheres published paper can be viewed here: https://doi.org/10.1029/2023JD040429.

Relative contributions of Atlantic (ATL), tropical Indian Ocean (TIO), and Pacific (minus ATL+TIO) SST basins to simulated westward extensions driven by two underlying SST gradient patterns (COMP1 and COMP2). 

In this study, we examine the strong link between winter and summer Rossby wave breaking (RWB) shear impacts and assess whether a winter RWB predictor improves extended-range forecast skill of seasonal North Atlantic tropical cyclone activity.

This published paper can be accessed here: https://doi.org/10.1175/JCLI-D-21-0213.1 .

August 2022 Rossby Wave Breaking over the North Atlantic basin observed in the 350-K potential vorticity anomaly field. As the Rossby wave breaks, streams of high-PV air move equatorward increasing the deep-layer vertical wind shear in the tropical environment.