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Changing wind extremes in the Great Lakes region in VR-CESM

Changes to the magnitude and frequency of midlatitude extreme winds under climate change are difficult to predict due to an inability to resolve the relevant submesoscale-to-mesoscale dynamics with traditional Earth system models. Recent work with the variable-resolution version of the NCAR Community Earth System Model (VR-CESM) has shown that, with 7 km refinement, it is capable of resolving local sensible heat flux and static stability signatures that contribute to the evolution of extreme winds under climate change, thereby producing more reliable projections than its 100 km uniform-resolution counterpart. In this study, we build on this previous work by assessing the effect of resolution on the turbulent spectrum, understanding the role of the diurnal cycle in extreme wind events, and investigating the seasonality of extreme wind events in the Southern Ontario region in VR-CESM under RCP8.5 end-of-century forcing. We describe the model representation of the drivers of extreme wind events in the high resolution domain, and how the evolution of these drivers under climate change impacts the intensity and frequency of extreme events across seasons. This work highlights the importance of considering seasonal and diurnal effects in studies of midlatitude wind extremes.

Host: Eylon Vakrat
Event series  Brewer-Wilson Seminar Series