我国南方冬季低温雨雪冰冻事件的大气扰动信号分析

利用中国549个站点的温度和降水资料确定了1960～2008年发生在我国南方冬季的23次低温雨雪冰冻事件。对全球大气变量再分析资料做物理分解得到天气尺度扰动分量用于这些事件的早期信号分析。结果表明，在低温事件发生时，南方地区上空300 hPa对应有最大负高度扰动，850 hPa有负温度扰动。这些扰动的传播特性可以作为低温事件发生的早期信号。在低温雨雪站日数大于10的11次事件中，它们的扰动信号平均可提前11.2天追踪到。

Analysis on Atmospheric Anomalous Signals of Winter Low Temperature and Snow-Ice Storms in Southern China

In this study, a total of 23 winter snow-ice storms in southern China were determined based on the homogenized daily minimum temperature series and precipitation datasets at 549 stations from 1960 to 2008. By decomposing atmospheric variables into four components, the synoptic-scale atmospheric anomalies of these storms were analyzed. The centers of negative geopotential height anomalies and negative temperature anomalies were found at 300 hPa and 850 hPa, respectively, when surface weather events occurred. The centers of these anomalies can be traced as early signals to indicate the occurrence of surface snow-ice storm events. On an average, the early signals of 11 major snow-ice storm events were identified 11.2 days earlier.