华南冬季异常冷月预测概念模型Ⅰ──500hPa高度场和海温场特征

SCHEMATIC PREDICTIVE MODEL FOR EXTREMELY SEVERE COLD MONTHS IN SOUTH CHINA WINTER ──500hPa geopotential field and SST field

确定了近 ４５年华南冬季异常冷月出现的时间，分析了其同期至前期 ６个月 ５００ ｈＰａ位势高度场和海温场的特征．各异常冷月当月５００ｈＰａ高度场有相似的特征，亚洲一太平洋地区高度场的特征是北高南低，经向环流发展。给出了前期５００ｈＰａ高度场差异显著月的距平特征．华南冬季各异常冷月至其前期６个月海温距平分布有持续性的特征，１月及其前期１～６个月赤道东太平洋ＳＳＴ呈Ｅ１ Ｎｉｎｏ特征， ２月和１２月呈Ｌａ Ｎｉｎａ特征．

The work sets the time for the occurrence of extremely severe cold months over the past 45 years in South China winter and studies the 500 hPa geopotential fields and SST fields in and before the months. The months have similar 500 hPa heights; higher in the north and lower in the south in the Asian-Pacific region, indicating meridianal evolution of the circulation. The work also gives the anomalies for months that have significant differences in the 500 hPa field in periods prior to the extremely severe cold months. Persistence is found in the SST anomalies in the current month and 1-6 months before them : January is featured by the EI Nino event and February and December by La Nina.