| 摘要: |
| 利用湖北省2013—2018年6—8月ADTD闪电探测数据对该地区的闪电活动进行特征分析后发现，地闪密度和日变化特征与地形密切相关，其中，闪电密度高值区出现在海拔500～1 500 m的中尺度山脉向平原的过渡地带以及山脉之间的平原(河谷)地区；山区的地闪集中在午后至傍晚时段，具有明显的单峰特征，平原的地闪日变化相对平缓，虽然主峰值同样出现在午后，但夜间地闪活动依然活跃。基于2015—2016年6—8月逐6 min雷达组合反射率拼图产品和地闪资料挑选了94例伴有显著闪电活动的雷暴系统个例，经统计分析后发现，雷暴系统的初次地闪、峰值地闪和末次地闪均集中出现在13:00—18:00，其中，山区雷暴的地闪持续时间较短，地闪频数峰值较小；平原雷暴的地闪持续时间更长，地闪频数峰值也更大；山麓雷暴的特征则介于两者之间。利用ERA-Interim再分析资料进行成因分析后可知，地形强迫和局地热力不稳定是影响湖北山区夏季闪电密度分布和日变化特征的关键因子。 |
| 关键词: 雷暴 地形 日变化 地闪密度 统计分析 |
| DOI：10.16032/j.issn.1004-4965.2021.031 |
| 分类号: |
| 基金项目: |
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| GROUND LIGHTNING ACTIVITY OF THUNDERSTORMS OVER DIFFERENT TOPOGRAPHY IN CENTRAL CHIN |
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YU Rong1,2, ZHANG Xiaoling3, DU Muyun4, MA Hedi4, YUAN Haifeng5, ZHU Chuanlin6
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1. Hubei Lightning Protection Center, Wuhan 430074, China;2. Institute of Heavy Rain, China Meteorological Administration, Wuhan 430205, China;3.National Meteorological Center, Beijing 100081, China;4.Institute of Heavy Rain, China Meteorological Administration, Wuhan 430205, China;5.Hubei Cartographic Institute, Wuhan 430074, China;6.Hubei Lightning Protection Center, Wuhan 430074, China
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| Abstract: |
| Based on ADTD lightning detection data from June to August in Hubei Province during 2013—2018, the present study analyzes the characteristics of lightning density and diurnal variation and finds their close relationship with topography. The high value of lightning density appears in the transition zone from mesoscale mountains to plains and the plains (valleys) between mountains at an altitude of 500～1 500 m. In the mountainous area, lightning mainly occurs in the period from afternoon to evening, showing obvious unimodal characteristics. By contrast, in the plain, the diurnal variation of the lightning is relatively gentle. Although the main peak value also appears in the afternoon, the lightning activity is still active at night. The present study also analyzes the 6 min data that combine radar composite reflectivity and cloud-to-ground (CG) flash data from June to August during 2015—2016 and selects 94 thunderstorm cases with significant lightning activity. The statistical analysis indicates that the first, peak and final CG flash of the thunderstorm system mainly occur in the afternoon (13:00—18:00). Among them, the mountain thunderstorms have shorter lightning duration and smaller peak of lightning frequency, those of plain thunderstorms are much longer and larger, and the characteristics of thunderstorms in the foothills are somewhere in between. Using the ERA-Interim reanalysis data, the present study finds that topographic forcing and local thermal instability are the key factors affecting the distribution and diurnal variation of summer lightning density in the mountainous areas of Hubei Province. |
| Key words: thunderstorm CG flash topography diurnal variation |
