Madden-Julian oscillation influences United States springtime tornado and hail frequency
Madden-Julian oscillation influences United States springtime tornado and hail frequency
复制标题
DOI：
10.1038/s41612-022-00263-5
复制
发表时间：
2022-05
影响因子：
9
通讯作者：
Douglas E. Miller;Vittorio A. Gensini;B. Barrett
中科院分区：
文献类型：
--
作者：
Douglas E. Miller;Vittorio A. Gensini;B. Barrett
麦登-朱利安涛动（MJO）是热带季节内变率的主要模式，并通过调节天气大气条件对温带极端天气产生影响。MJO相位与美国的异常龙卷风和强冰雹频率相关。然而，这种关系的稳健性尚不确定，尽管龙卷风和冰雹会引起社会经济影响，但人们对调节物理途径的可变性知之甚少。我们使用五次MJO指数和几乎完美的恶劣天气预报来解决这个问题。MJO生命周期进行了编目和聚类，以记录变异性和增强亚季节龙卷风和冰雹可预测性的潜在途径。在1979-2019年北方春季期间，与经历屏障效应的47次MJO事件相比，在经过海洋大陆传播的53次活跃MJO事件的最强高层辐散期后3-4周，美国龙卷风和冰雹概率的统计显著增加。通过海洋大陆传播的53个MJO事件揭示了三个主要的MJO演变-每个都包含独特的路径和美国龙卷风和冰雹频率的调制-提高了我们在延长提前时间内预测这些危害的知识和能力。
The Madden–Julian Oscillation (MJO) is the dominant mode of intraseasonal variability in the tropics and has a documented influence on extratropical extreme weather through modulation of synoptic atmospheric conditions. MJO phase has been correlated with anomalous tornado and severe hail frequency in the United States (US). However, the robustness of this relationship is unsettled, and the variability of physical pathways to modulation is poorly understood, despite the socioeconomic impacts that tornadoes and hail evoke. We approached this problem using pentad MJO indices and practically perfect severe weather hindcasts. MJO lifecycles were cataloged and clustered to document variability and potential pathways to enhanced subseasonal tornado and hail predictability. Statistically significant increases in US tornado and hail probabilities were documented 3–4 weeks following the period of the strongest upper-level divergence for the 53 active MJO events that propagated past the Maritime continent, contrasting with the 47 MJO events that experienced the barrier effect, during boreal spring 1979–2019. The 53 MJO events that propagated past the Maritime continent revealed three prevailing MJO evolutions—each containing unique pathways and modulation of US tornado and hail frequency—advancing our knowledge and capability to anticipate these hazards at extended lead times.