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Topic

Climate Variability of Seasonal Wind Extreme Events in North America

School of Earth and Ocean Sciences

Date & location

• Tuesday, April 15, 2025
• 12:00 P.M.
• David Strong Building, Room C130

Examining Committee

Supervisory Committee

• Dr. Adam Monahan, School of Earth and Ocean Sciences, University of Victoria (Supervisor)
• Dr. Roberta Hamme, School of Earth and Ocean Sciences, UVic (Member)
• Dr. Tara Troy, Department of Civil Engineering, UVic (Outside Member)

External Examiner

• Dr. David Atkinson, Department of Geography, UVic

Chair of Oral Examination

• Dr. Michael Paskevicius, Department of Curriculum and Instruction, UVic

Abstract

This study investigates the climate variability and seasonal predictability of large-scale wind extreme events across North America, with a particular focus on their relationship with Pacific sea surface temperature (SST) patterns. Wind Droughts (WD) and Wind Floods (WF) are defined as prolonged seasonal anomalies in surface wind speed, with substantial implications for climate science and renewable energy systems. Using large ensembles of historical simulations from three climate models (CanESM2, CanRCM4, and CESM2), we analyze the frequency, spatial distribution, and predictability of these extreme events across six North American regions.

Time-series analysis reveals that WF events occur most frequently in northern regions during winter, while WD events are more prevalent in southern regions during summer. Composite wind and SST anomaly maps indicate distinct and largely opposing patterns associated with WF and WD events in most regions in North America. WD events are characterized by a band of warm anomalies in the Gulf of Alaska—occasionally extending into the subtropical and tropical Pacific—coupled with a contrasting band of cold anomalies spanning from Asia to the eastern Pacific, whereas WF events display the opposite pattern. In the Southeast of North America (SENA), however, wind extremes exhibit a localized response with a reversed SST pattern, likely tied to the Pacific–North American (PNA) pattern.

Furthermore, our evaluation of the predictive skill of Pacific SST anomalies shows that WF events are more predictable than WD events, with extratropical Pacific SST anomalies enhancing predictability more effectively than equatorial or full-basin SST patterns. Importantly, the relationships between SST patterns and WD/WF events are predominantly statistically significant at the 5% level, further bolstering confidence in SST-based seasonal predictability. These findings provide new insights into the large-scale drivers of wind extremes and their seasonal predictability, offering valuable implications for renewable energy resource management and climate modeling.