Based on observational analyses and on-site ground and aerial damage surveys, this work aims to reveal the weather phenomena-especially the wind situation-when Oriental Star capsized in the Yangtze River on June 1, 2015. Results demonstrate that the cruise ship capsized when it encountered strong winds at speeds of at least 31 m s-1 near the apex of a bow echo embedded in a squall line. As suggested by the fallen trees within a 2-km radius around the wreck location, such strong winds were likely caused by microburst straight-line wind and/or embedded small vortices, rather than tornadoes.
2015年6月1日,长江流域湖北监利航段发生了“东方之星”号客轮特大倾覆事故,造成442人遇难。本文基于雷达观测和地面及无人机航拍灾害调研,揭示了事故时段的天气现象,尤其是风力情况。研究表明,客轮在倾覆时处于一条飑线的弓形回波前缘,遭遇了至少31 m/s的强风。客轮倾覆位置2 km范围内的树木倒伏特征表明,该强风可能是由微下击暴流里的直线大风或其中的小尺度涡旋造成,而并非龙卷。.
Keywords: Bow echo; Damage survey; Drone; Microburst; Squall line; Tornado.