广州市低温日的气候特点及其变化

统计了1951～2008年广州市最低气温≤5℃的低温日数，发现近58年来呈现年低温日数减少、低温终日提前、低温期缩短的趋势，年低温日数主要有2～3年和7～8年的变化周期。对低温日数异常年景冬季500hPa环流进行合成分析发现，广州年低温日数显著偏多和偏少年份的亚欧地区冬季500hPa高度距平场基本呈反位相分布。另外，冬季处于E1 nino位相时广州低温日数以偏少为主，La nina位相时低温日数以偏多为主。

Climate Features and the Variations of Low-temperature Days in Guangzhou

By statistics of the low temperature days(LTD,the day with minimum temperature equal or lower than 5℃) from 1951 to 2008 in Guangzhou,trends are found that,during the past 58 years,the LTD ends earlier and earlier,and the annual number of LTD has been declining,as well as the duration of it.Annual number of LTD has periods of 2~3 and 7~8 years.By composite analysis on winter circulations at 500 hPa during anomalous years,the potential height anomaly fields at 500 hPa in the anomalous years with more LTD are found to be opposite in phase to that in the anomalous years with less LTD.Guangzhou with winter in El Nio phase has less LTD and vice versa in La Nina phase.