Severe hail activities have significant impacts on our society because they damage property and are dangerous to people and animals. However, we have little knowledge on recent changes in geographic locations of severe hail activity center over Canada. Prior to exploring this, we have carried out Canada hail data consistency and reliability checks using solid trend analyses of three independent methods for time series of hail counts and days, and robust verifications of reported hail data by a recently developed approach of sample generation by replacement. Here, we discover for the first time a statistically significant east shift of Canada severe hail activity and total hail activity using discriminant analysis. The spatial shift is from the western portion of continental Canada during 2005–2013 to the eastern Canada with a maritime environment during 2014–2022. With increase of hail severity, the hail activities increase from the colder period 2005–2013 to the warmer period 2014–2022. Our composite analyses show that over the continental Canada, the hail activities are enriched through thermodynamically driven convective instability and precipitable water associated with the warming climate, as well as dynamically driven processes such as vertical wind shear and vertically integrated water vapor flux convergence. Over the maritime Canada with the colder condition, the hail activities are enhanced by dynamically driven moisture advection and convergence as well as vertical wind shear, thermodynamically driven process of precipitable water, and partially due to convective instability. This research promotes our understanding of climate change impact on hail activities, shedding lights on long-term hail projection, adaptation, and mitigation strategies.

中文翻译：

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气候变化下加拿大东移严重冰雹活动


严重的冰雹活动对我们的社会有重大影响，因为它们会损害财产并对人和动物构成危险。然而，我们对加拿大上空严重冰雹活动中心的地理位置的近期变化知之甚少。在探索这一点之前，我们已经对冰雹计数和天数的三种独立方法进行了可靠的趋势分析，并通过最近开发的替代样本生成方法对报告的冰雹数据进行了稳健的验证。在这里，我们首次使用判别分析发现了加拿大严重冰雹活动和总冰雹活动具有统计学意义的东移。空间转移从 2005-2013 年的加拿大大陆西部到 2014-2022 年期间具有海洋环境的加拿大东部。随着冰雹严重程度的增加，冰雹活动从 2005-2013 年的较冷期增加到 2014-2022 年的较暖期。我们的综合分析表明，在加拿大大陆上，冰雹活动通过热力学驱动的对流不稳定性和与气候变暖相关的可降水，以及动态驱动的过程（如垂直风切变和垂直整合水蒸气通量收敛）而丰富。在较冷条件的加拿大沿海地区，冰雹活动因动态驱动的水汽平流和辐合以及垂直风切变（热力学驱动的可降水过程）而增强，部分原因是对流不稳定性。这项研究促进了我们对气候变化对冰雹活动影响的理解，为长期冰雹预测、适应和缓解策略提供了启示。