ABSTRACT This study explores the causes of a severe thunderstorm outbreak north of 70°N on 24–25 July 2014 and provides the first characterization of lightning over the Canadian Arctic Islands. Lightning data were obtained from the Global Lightning Dataset (GLD360) network. Convective available potential energy calculated using representative soundings and surface conditions indicated high instability that, combined with large vertical wind shear and storm-relative helicity, likely caused severe thunderstorms to form over Victoria Island. These storms subsequently drifted northeastward over Parry Channel, where they transitioned into elevated storms and travelled as far north as and passed close to Grise Fiord (76.4°N). Satellite imagery suggested that overshooting tops reached 11.6 km. The GLD360 network detected more than 15,000 strokes north of the Arctic Circle and an unusually high ratio of positive strokes during this outbreak.

中文翻译：

---

加拿大北极群岛以北 70°N 发生严重雷暴爆发，具有不寻常的闪电特征

摘要 本研究探讨了 2014 年 7 月 24 日至 25 日在 70°N 以北爆发严重雷暴的原因，并首次提供了加拿大北极群岛上空闪电的特征。闪电数据来自全球闪电数据集 (GLD360) 网络。使用代表性探测和地表条件计算的对流可用势能表明高度不稳定性，再加上大的垂直风切变和风暴相对螺旋度，可能导致维多利亚岛上空形成严重的雷暴。这些风暴随后向东北飘过帕里海峡，在那里转变为高架风暴，向北移动并靠近格瑞斯峡湾 (76.4°N)。卫星图像表明，顶峰达到了 11.6 公里。GLD360 网络检测到超过 15 个，