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

最近的科学研究已开始解开北极变暖与极端天气事件频率增加之间的复杂关系。已经假设了这种联系的几种机制，最近的研究表明，不同的机制可能因季节和地区而异。这项研究推进了我们对北方大陆冬季和夏季过去和未来极端天气事件趋势的认识，以及北极快速变暖在促成这些事件频率和持续性变化方面的作用。气候模式在捕捉这些关系的现实主义进行评估，结果有助于改善模式模拟。极端天气频率的增加已经直接影响到地球仪上数百万甚至数十亿人。这项研究项目的结果是有价值的规划者，商业领袖和决策者在未来的极端天气事件的增加做好准备，这项研究建立在以前的工作相关的北极变化和统计协会与极端冬季天气事件，其中观测数据集被用来建立北极温暖异常事件和北美东部地区的严冬天气之间的联系。研究小组将这种方法扩展到：1）再分析和气候模型模拟的网格数据集，允许探索所有北方半球中纬度地区的关系，2）冬季和夏季，以及3）历史和未来预测。这项研究将极大地扩展我们对北极变暖放大（AAW）与极端夏季和冬季天气条件之间统计关联的了解，这将为正在进行的联系机制研究提供信息。这项研究专门回答了与验证，可变性，过去和未来的演变，归因，历史模型模拟的现实主义和持久性有关的问题。社会各阶层的决策者迫切需要更好地了解和更准确地预测极端天气的频率、位置和严重程度的变化。这项研究的结果为各种推广模式提供了信息和加强，为决策者提供了有价值的可操作信息，并创建了新的极端天气指数数据集，可供其他研究人员纳入研究。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

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.