山西省电线积冰特征分析与一种基于环流指数预测方案的研究

Feature analysis of wire icing in Shanxi province and the studies on a prediction scheme using circulation indices

摘要:

基于1980—2019年间山西省16个电线积冰观测站的逐日资料，通过积冰日数、平均标准冰厚、最长积冰持续日数、最大标准冰厚构建了五台山、北部、中部、南部4个区域的综合电线积冰强度指数。在此基础上，运用趋势检验、集合经验模态分解、时滞相关、线性判别等方法分析了积冰变化趋势及其对24种环流因子的响应特征。结果表明：除五台山全年多个月份发生积冰外，其他区域积冰主要集中在冬季1月和12月，并且五台山呈现出更高的强度。北部、中部及五台山的积冰强度均呈现减弱趋势，而南部则呈现显著的增强趋势。积冰强度与环流因子之间存在显著的时滞相关性，特别是前期多个重要环流指数特征值驱动的线性判别模型对关键月份的强度等级有着较好的预判效果。

Abstract:

Based on the daily data from 16 wire icing observation stations in Shanxi Province between 1980 and 2019, a comprehensive wire icing intensity index using icing days, average standard ice thickness, longest continuous icing duration, and maximum standard ice thickness was constructed for four regions such as Wutai Mountain, northern, central, and southern areas. On this basis, trend tests, ensemble empirical mode decomposition, time-lag correlation, and linear discriminant analysis were employed to examine the trends in icing changes and their response characteristics to 24 circulation factors. The results indicated that: except for Wutai Mountain where icing occurred across many months of the year, icing in other regions was primarily concentrated in winter months, particularly January and December. Additionally, Wutai Mountain exhibited higher icing intensity. The icing intensity in the northern, central, and Wutai Mountain regions showed a weakening trend, while the southern region displayed a significant increasing trend. Significant time-lag correlations existed between icing intensity and circulation factors. Notably, a linear discriminant model driven by characteristic values of multiple key circulation indices from preceding periods demonstrated effective predictive performance for the intensity levels in critical months.