嵌入注意力机制的深度学习闪电短临预报方法研究
Deep Learning-Based Lightning Nowcasting with Embedded Attention Mechanisms
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摘要: 闪电的空间尺度变化范围广泛,发生突然、生命史短且演变迅速,其高时空分辨精细预报极为困难。本研究利用深度学习数据驱动的优势,建立适应多种数据源的多层UNet结构神经网络并添加注意力机制,以此构建华北地区闪电短临预报深度学习模型AME-UNet。使用国家电网闪电定位数据和新一代静止气象卫星FY-4A高时空分辨率数据,引入表征云顶发展高度和冻结的具有明确物理意义的亮温通道差作为预报因子,用以实现未来0-1h与1-2h闪电发生与否的逐像素预报。结果表明AME-UNet模型在闪电短临预报任务中展示了良好的应用潜力,0-1h命中率最高达0.46,虚警率为0.29,1-2h命中率最高达0.41,虚警率为0.44。本研究为基于深度学习开展闪电短临预报提供了新思路和新方法。Abstract: Lightning events exhibit significant variability in spatial scale, occur suddenly, have short lifespans, and evolve rapidly, making high-resolution forecasting particularly challenging. This study leverages the data-driven capabilities of deep learning to construct a multi-layer UNet neural network architecture with an embedded attention mechanism, resulting in the AME-UNet model for lightning nowcasting in North China. The model integrates lightning location data from the State Grid of China with high spatiotemporal resolution data from the FY-4A geostationary meteorological satellite. Brightness temperature channel differences, which effectively represent cloud-top development heights and freezing levels with clear physical significance, are introduced as predictors for pixel-wise lightning nowacasting for 0-1h and 1-2h timeframes. Results indicate that the AME-UNet model holds promising potential for lightning nowcasting, achieving a maximum hit rate of 0.46 and a false alarm rate of 0.29 for the 0-1 hour forecast, and a hit rate of 0.41 with a false alarm rate of 0.44 for the 1-2 hour forecast. This study offers innovative approaches to deep learning-based lightning nowcasting, expanding the toolkit available for severe weather nowcasting.