Collaborative Research: Influences of Amplified Arctic Warming on Extreme Weather in Midlatitudes

Atmospheric And Environmental Research Inc, Lexington MA

Investigators

Abstract

Recent scientific studies have begun to disentangle the complex relationship between Arctic warming and the increased frequency of extreme weather events. Several mechanisms for this linkage have been hypothesized, and recent studies reveal that different mechanisms can vary by season and region. This research advances our knowledge of trends in past and future extreme weather events during winter and summer over northern hemisphere continents, and the role of rapid Arctic warming in contributing to changes in the frequency and persistence of those events. The realism of climate models in capturing these relationships are assessed, and results aid in improving model simulations. Increased frequency of extreme weather is already directly affecting millions, if not billions, of people across the globe. The results from this research project are valuable to planners, business leaders, and decision-makers in preparing for future increases in extreme weather events. This study builds upon previous work related to Arctic variability and statistical associations with extreme winter weather events in which observational datasets were used to establish a link between episodes of Arctic warm anomalies and severe winter weather at locations in eastern North America. The research team expands this methodology to, 1) gridded data sets from reanalysis and climate model simulations, allowing exploration of relationships across all northern hemisphere midlatitude areas, 2) both winter and summer seasons, and 3) historical and future projections. The study will greatly expand our knowledge of statistical associations between amplified Arctic warming (AAW) to extreme summer and winter weather conditions that will inform ongoing studies of linkage mechanisms. This research specifically answers questions related to validation, variability, past and future evolution, attribution, realism of historical model simulations, and persistence. A better understanding and more accurate prediction of changes in the frequency, location, and severity of weather extremes are urgently needed by decision-makers at all levels of society. Results from this study inform and enhance various modes of outreach, provide valuable and actionable information to decision-makers, and create new data sets of extreme weather indices that can be incorporated into studies by other investigators. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.