| 2013年春季一次强飑线过程中尺度特征研究 |
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| 引用本文： | 吴瑞姣,黎玥君,林永辉.2013年春季一次强飑线过程中尺度特征研究[J].热带气象学报,2023(4):522-535. |
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| 作者姓名： | 吴瑞姣 黎玥君 林永辉 |
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| 作者单位： | 1.中国气象科学研究院灾害天气国家重点实验室，北京100081；3.安徽省气象台，安徽合肥230031;2.浙江省气象科学研究所，浙江杭州310008 |
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| 摘 要： | 运用多种观测数据，结合WRF模式分析了2013年3月19日发生在黔湘地区一次飑线形成期的中尺度特征。（1） 此次飑线发生在高空500 hPa槽前的西南气流中，地面冷锋附近。环境风为西南向，且垂直于飑线长轴的分量小于沿着飑线长轴的分量。（2） 飑线东、西两段存在显著差异：东段所在环境干燥，下沉对流有效位能DCAPE大，故雷暴大风强而短时强降水弱，对流单体初始于锋区及冷空气一侧，呈碎块状分布；西段环境湿润，短时强降水和冰雹集中，对流单体出现于地面锋区附近中尺度辐合线内，辐合线持久，其上辐合中心处不断有单体新生。（3） 此次过程有重力波作用，且飑线西段重力波特征更明显。急流中的波动与中尺度辐合线相交，波动上升气流叠加辐合线上升运动，引起对流发生并迅猛发展，使得对流单体趋向于沿着波动等振幅面排列成带状，进而形成飑线。（4） 旧单体南、北两侧均有新对流单体发生：北侧新单体高、低层重力波反相位叠加，对流受到抑制；南侧的新单体高、低层波动同相，上升气流加强，对流得以发展；新旧单体不断迭代更新，飑线整体向东南传播。
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| 关 键 词： | 斜压锋生 飑线 对流单体 中尺度 重力波 |
MESOSCALE FEATURES OF A SQUALL LINE IN SPRING 2013 |
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| WU Ruijiao,LI Yuejun,LIN Yonghui.MESOSCALE FEATURES OF A SQUALL LINE IN SPRING 2013[J].Journal of Tropical Meteorology,2023(4):522-535. |
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| Authors: | WU Ruijiao LI Yuejun LIN Yonghui |
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| Institution: | 1.State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Science, Beijing 100081, China;3.Anhui Meteorological Observatory, Hefei 230031, China;2.Zhejiang Institute of Meteorological Science, Hangzhou 310008, China |
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| Abstract: | Based on several kinds of observational data and numerical simulation, the mesoscale features of a strong squall line on March 19, 2013, in southern China were investigated. The results show that: (1) The squall line occurred in front of a 500-hPa trough and was near a cold front on the ground. The ambient wind was mainly southwestern, and its cross-line component was smaller than the along-line component. (2) There were significant differences between the east and the west of the squall line. The eastern part was dry, and the DCAPE was large; as a result, short-term heavy rainfall was weaker than that in the western part, while thunderstorm gales were stronger. Convective cells in the eastern part initially distributed in a fragmented manner at the cold side of the frontal zone. The western part was humid, with short-term heavy rainfall and concentrated hail. Convective cells appeared within the mesoscale convergence line near the surface front area, and the convergence line was persistent. There are constantly new cells growing at the convergence center above them. (3) The gravity waves affected the maintenance of the squall line, and their effect in the western part was obviously stronger than that in the eastern part. When the updraft of the jet intersected with the convergent line, the lower-level updraft at the intersection strengthened and led to convective initiation (CI). Finally, the squall line formed along the amplitude of the gravity waves. (4) New convective cells emerged in both the north and the south of older cells. The upper and lower gravity waves of those new cells in the north were out of phase, restraining the convection; however, they were in phase in the southern new cells, which positively contributed to CI. New cells continued to emerge and replaced old ones, and the squall line propagated to the southeast. |
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| Keywords: | baroclinic frontogenesis squall line convection cell mesoscale gravity wave |
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