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投稿时间:2024-11-24 修订日期:2026-01-22
投稿时间:2024-11-24 修订日期:2026-01-22
中文摘要: 强对流大风(简称强风)发生频次随风速增大而急剧减少的现象,是导致现有各类算法难以对其进行分级识别的主要原因。为了解决该问题,将不可微分命中率(POD)作为卷积神经网络(CNN)的损失函数,偏差(Bias)为其约束条件,利用多目标优化的免疫进化算法(MOIEA)优化CNN的所有模型参数,提出了一种针对17.2、20.8、24.5 m·s-1(分别对应8、9、10级风力)以上强风的分级识别算法(severe convective wind identification network,SCWINet)。SCWINet利用2022—2024年浙江省雷达垂直液态水含量、三维雷达反射率、闪电定位仪、分钟级地面自动观测站资料,实现了时间分辨率为6 min、空间分辨率为0.01°的强风分级识别,并与加权均方误差可微分损失函数和平衡均方误差可微分损失函数进行对比,模型结构均一致。然后基于邻域法(扫描半径为5 km)的TS评分、Bias、POD、虚警率和强风平面分布特征探讨了SCWINet的适用性。主要结果如下:SCWINet 能有效分级识别出系统性和分散性强对流系统对应的17.2、20.8、24.5 m·s-1以上强风,其中对系统性强对流触发的强风分级识别效果要优于分散性强对流。此外,分级识别效果总体随强风风速的增大而降低,空报和漏报的增大是造成上述现象的主要原因。加权均方误差和平衡均方误差损失函数则没有任何识别能力,其识别出的风速均小于17.2 m·s-1。未来可通过增加输入特征和数据量,进一步提升其识别准确性,并推广至更强风速的识别中。
中文关键词: 临近预报,强对流大风,分级识别,深度学习,损失函数,雷达
Abstract:The serious imbalance in sample distribution, characterized by a sharp drop in the frequency of severe convective winds with increasing wind speeds, is identified as the predominant factor hindering the accurate intensity-based classification of severe convective winds by various existing algorithms.To address this problem, in this study the non-differentiable probability of detection (POD) is proposed to be the loss function for a convolutional neural network (CNN) and Bias to be its constraint condition. Subsequently, the multi-objective optimization immune evolution algorithm (MOIEA) is employed to optimize all the model parameters of the CNN. This contributes to the development of a novel identification algorithm, which is named severe convective wind identification network (SCWINet), for identifying severe convective winds at the speeds of 17.2, 20.8, 24.5 m·s-1 and above. SCWINet leverages the radar vertical liquid water content, three-dimensional radar reflectivity, lightning location data and minutely surface automatic observation station data in Zhejiang Province during 2022-2024, achieving different levels of severe convective wind identification with temporal resolution of 6 minutes and spatial resolution of 0.01°. Then, the performance of SCWINet is compared to weighted mean-square error (WMSE) and balanced mean-square error (BMSE), which use the same CNN structure but have differentiable loss functions. The applicability of SCWINet is then assessed based on the threat score, Bias, POD, false alarm ratio that uses the neighborhood method (with a scanning radius of 5 km), and the planar distribution characteristics of severe convective winds. The main results are as follows. SCWINet can effectively identify severe convective winds of 17.2, 20.8, 24.5 m·s-1 and above corresponding to systematic and scattered severe convective systems, with better performance observed in identifying severe convective winds triggered by systematic convection than those triggered by scattered convection. However, the identification effectiveness of SCWINet generally decreases as wind speed increases, with increased false alarms and missed detections being the primary causes of this phenomenon. By contrast, the commonly used WMSE and BMSE approach-es fail to identify severe convective winds, and all severe convective winds they identify are below 17.2 m·s-1.Nevertheless, the data used in this study are somewhat limited in terms of the feature completeness and volume. Future enhancements in identification accuracy of severe convective winds could be achieved by incorporating additional features and data, such as radar radial velocity, specific differential phase, differential reflectivity, and satellite data. This could be also applied to identify even higher wind speeds.
keywords: nowcasting, severe convective wind, level identification, deep learning, loss function, radar
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基金项目:浙江省气象局科技计划项目(2023ZDZL01)、浙江省自然科学基金联合基金资助项目(LZJMY25D050004、LZJMY23D050005、LZJMY23D050001)、浙江省科技厅“尖兵领雁”项目(2022C03150)、浙江省气象局科技计划项目(2024ZDZL02)、宁波市公益性项目(2025S111)和中国气象局复盘总结专项(FPZJ2024-051) 共同资助
引用文本:
罗玲,张智察,赵军平,陈列,黄旋旋,王丽颖,李文娟,罗然,彭霞云,黄娟,2026.基于免疫进化算法优化卷积神经网络的强对流大风分级识别方法及其应用[J].气象,52(4):454-464.
LUO Ling,ZHANG Zhicha,ZHAO Junping,CHEN Lie,HUANG Xuanxuan,WANG Liying,LI Wenjuan,LUO Ran,PENG Xiayun,HUANG Juan,2026.Identification Method of Different Levels of Severe Convective Winds with Convolutional Neural Networks Optimized by Immune Evolutionary Algorithm and Its Application[J].Meteor Mon,52(4):454-464.
罗玲,张智察,赵军平,陈列,黄旋旋,王丽颖,李文娟,罗然,彭霞云,黄娟,2026.基于免疫进化算法优化卷积神经网络的强对流大风分级识别方法及其应用[J].气象,52(4):454-464.
LUO Ling,ZHANG Zhicha,ZHAO Junping,CHEN Lie,HUANG Xuanxuan,WANG Liying,LI Wenjuan,LUO Ran,PENG Xiayun,HUANG Juan,2026.Identification Method of Different Levels of Severe Convective Winds with Convolutional Neural Networks Optimized by Immune Evolutionary Algorithm and Its Application[J].Meteor Mon,52(4):454-464.
